Next Article in Journal
Serum Levels and Removal by Haemodialysis and Haemodiafiltration of Tryptophan-Derived Uremic Toxins in ESKD Patients
Next Article in Special Issue
Proteomic Research in Peritoneal Dialysis
Previous Article in Journal
Molecular Mechanisms: Connections between Nonalcoholic Fatty Liver Disease, Steatohepatitis and Hepatocellular Carcinoma
Previous Article in Special Issue
The Cannabis Proteome Draft Map Project
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Review

Review of Three-Dimensional Liquid Chromatography Platforms for Bottom-Up Proteomics

College of Pharmacy, Gachon University, Incheon 21936, Korea
*
Author to whom correspondence should be addressed.
These authors contributed equally to this work.
Int. J. Mol. Sci. 2020, 21(4), 1524; https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21041524
Submission received: 4 February 2020 / Revised: 19 February 2020 / Accepted: 21 February 2020 / Published: 23 February 2020
(This article belongs to the Special Issue Advances in Proteomic Research)

Abstract

:
Proteomics is a large-scale study of proteins, aiming at the description and characterization of all expressed proteins in biological systems. The expressed proteins are typically highly complex and large in abundance range. To fulfill high accuracy and sensitivity of proteome analysis, the hybrid platforms of multidimensional (MD) separations and mass spectrometry have provided the most powerful solution. Multidimensional separations provide enhanced peak capacity and reduce sample complexity, which enables mass spectrometry to analyze more proteins with high sensitivity. Although two-dimensional (2D) separations have been widely used since the early period of proteomics, three-dimensional (3D) separation was barely used by low reproducibility of separation, increased analysis time in mass spectrometry. With developments of novel microscale techniques such as nano-UPLC and improvements of mass spectrometry, the 3D separation becomes a reliable and practical selection. This review summarizes existing offline and online 3D-LC platforms developed for proteomics and their applications. In detail, setups and implementation of those systems as well as their advances are outlined. The performance of those platforms is also discussed and compared with the state-of-the-art 2D-LC. In addition, we provide some perspectives on the future developments and applications of 3D-LC in proteomics.

1. Introduction

Proteomics is the study of proteomes, aiming at globally characterizing all proteins in any given cell and evaluating protein functions, modifications, and interactions between them [1]. As proteins play a crucial role in cell structure, metabolic processes, and regulatory mechanisms, proteomics is beneficial to assess current cell status, and thereby elucidate disease mechanisms and identify potential candidates for biomarker [2,3,4,5]. However, proteomes are much more complex and dynamic than genomes, as evidenced by the presence of a larger number of proteins compared to genes, which raises more challenges to proteomics from separation to detection [6]. Proteome separation and identification are mainly based on two analytical strategies: Top-down and bottom-up approaches. Top-down proteomic studies use intact proteins for direct separation and identification, usually with liquid chromatography-tandem mass spectrometry (LC-MS/MS) [7]. Top-down proteomics has unique advantages for the comprehensive analysis of proteoforms, which arise from genetic variations, alternative RNA splicing, and post-translational modifications (PTMs) [8]. However, it still faces a number of challenges related to protein’s solubility, separation, ionization efficiency in MS analysis and quantification [9]. In contrast, the bottom-up proteomic approaches minimize the problems by analyzing peptides prepared from enzymatic proteolysis. However, the increased sample complexity requires higher separation power. To this end, multidimensional (MD) chromatography increasing peak capacity dramatically becomes the essential tool in proteome-wide analysis [10,11,12,13].
The simultaneous separation of a large number of peptides (up to hundred-thousands or millions) in a bottom-up proteomic sample raises great challenges to both LC and MS/MS. The depth of proteome coverage has been driven by developments in these techniques. The mass spectrometer has been considerably improved in the past decade with a dramatic increase in acquisition speed and mass accuracy as well as the introduction of new fragmentation techniques [14,15,16,17]. Regarding LC, various MD separation approaches have been developed to decrease the complexity of samples, by which, peptides are consecutively separated by two or more independent separation mechanisms [6,18,19]. MD-LC systems can be carried out in an online or offline manner. Ideally, each dimension in an MD-LC system is completely orthogonal to the others, and the theoretical peak capacity is defined as the product of the individual peak capacity. However, currently available MD-LC systems do not reach the perfect orthogonality due to their intrinsic imperfection and some practical limitations (e.g., band broadening caused by dead volumes) [6,20,21]. After the development of the first two-dimensional LC (2D-LC) system, which was multidimensional protein identification technology (MudPIT) [22], various combinations of MD-LC have been reported. Most of them are 2D-LC with various combinations, such as strong cation exchange chromatography (SCX)-reversed phase liquid chromatography (RPLC) [23,24,25,26,27,28], strong anion exchange chromatography (SAX)-RPLC [29], size exclusion chromatography (SEC)-RPLC [30,31], hydrophilic interaction chromatography (HILIC)-RPLC [32,33,34], RPLC-capillary zone electrophoresis (CZE) [35], and RPLC-RPLC [36,37,38,39,40].
Some previous reviews summarized the developments and advances of MD-LC systems and their applications in proteomics, most of which focused on 2D-LC systems [6,18,19,41,42,43,44,45,46,47]. In this review, we summarized recent advances in the development of 3D-LC separation techniques for proteomic application. Existing 3D-LC systems were classified and discussed regarding their setups. The power of 3D-LC compared to 2D-LC in increasing sensitivity and throughput for qualitative analysis is also discussed. Finally, we presented some perspectives on the future developments and applications of 3D-LC in proteomics.

2. Recent Developments and Applications of 3D-LC

Generally, an MD separation can be carried out in an online or offline manner. An offline setup is based on fractions’ collection in the first (and second) dimension and their analysis in the final dimension fashion. Each separation process of an offline system is conducted separately, suitable for conventional LC-MS/MS systems. Conversely, in an online platform, the eluent is directly transferred from the first dimension onto the next ones without flow interruption. Online systems, therefore, require unique and sophisticated setups [18]. In this review, existing 3D-LC platforms are classified into offline, online, and combined systems.

2.1. Offline 3D-LC Systems

At the early stage of 3D-LC, several 3D-LC systems were developed by modification of MudPIT. Most of them were based on the combination of SCX and RPLC since SCX-RPLC showed high orthogonality and high resolving power [48,49,50]. SCX enables peptide separation with respect to their ionic properties [51,52], whereas RPLC separates them based on their hydrophobicity to long carbon chain resins [53]. Utilizing this basis, Hood et al. performed 3D-LC (weak anion exchange/weak cation exchange-SCX-RPLC) to identify 1057 protein groups from mouse serum [54]. Later, Zhang et al. developed SEC-SCX-RPLC for proteomic analysis of normal human liver tissue with 1622 identified proteins [55]. Besides the development of SCX-RPLC, the combination of two RPLC implemented under extremely different pH conditions (usually high pH and low pH) was proven to be effective [56]. In 2006, Shen et al. described a 3D-LC system (RP-SCX-RP) for investigation of plasma proteome of patients with sepsis and systemic inflammatory response syndrome, which found 484 proteins with gene identification. This 3D-LC platform combined the two most popular 2D-LC approaches, SCX-RPLC and RPLC-RPLC [57]. After that, various offline 3D-LC were developed for proteomic applications, most of which utilized either SCX-RPLC or RPLC-RPLC.
Betancourt et al. developed a workflow consisting of SCX-RP-RP for proteomic profiling of mouse embryonic fibroblasts. Peptides were first subjected to the reversible labeling of their NH2 groups. Subsequently, they were separated according to their charge state by SCX into three fractions: neutral, singly, and multi-charged peptides. The peptides were further fractionated using RPLC at pH 10 to generate 30 SCX-RP fractions prior to RPLC (pH 2)–MS/MS analysis. This 3D-LC system allowed the identification of 5051 proteins from 29,843 peptides. This approach required the acylation of peptides’ amino groups before SCX fractionation and the regeneration of amino groups after that [58]. Zhao et al. utilized the same 3D-LC setup to investigate the human embryonic stem cell proteome. Four subcellular fractions were subjected to SCX and then RPLC fractionation with low-pH solvents (0.1% trifluoroacetic acid). The third separation step was also low-pH RPLC (0.1% formic acid). In total, triplicate analysis of 100 SCX-RPLC fractions resulted in the identification of 3184 proteins, more than 24,000 unique peptides, approximately 500 phosphorylation sites, and 68 sites of O-linked β-N-acetyl glucosamine modification [59]. Compared to the above-mentioned study with a similar setup [58], this study was quite modest regarding the numbers of protein and peptide identification. One possible explanation might come from the use of RPLC solvents. Generally, 2 RPLC dimensions are performed under different pH conditions to achieve good orthogonality [56]. The use of low-pH solvents in both second and third RPLC separation in this study might not demonstrate the best performance of the 3D-LC system.
Recently, a 3D-LC method was developed for an in-depth human urinary proteomic analysis. Peptides were first fractionated by gel-eluted liquid fraction entrapment electrophoresis (GELFrEE) or liquid-phase isoelectric focusing (LPIEF), which generated 12 and 6 fractions, respectively. Each fraction was further fractionated to 20 sub-fractions by high-pH RPLC prior to low-pH RPLC-MS/MS analysis. The number of protein identification in this study was relatively modest (more than 6000), particularly when considering the high number of fractions (360) and the long analysis time (720 h) [60]. Apart from the above-mentioned combinations, Spicer et al. developed an offline 3D platform consisting of three consecutive RPLC: a low-pH RPLC with heptafluorobutyric acid as an ion-pairing modifier, a high-pH RPLC, and a low-pH RPLC with formic acid as another ion-pairing modifier. A high degree of orthogonality was demonstrated using this 3D-LC system, which could identify over 14,000 proteins with 126 fractions. This 3D strategy required a long analysis time (nearly 8 days) and a relatively high sample amount (720 μg of peptides) [61]. Other combinations arising from either SCX-RPLC or RPLC-RPLC are also available. In a recent study, Boichenko et al. compared five different 2D-LC setups for the analysis of human plasma digests and selected the best two combinations to construct an optimal 3D-LC system: electrostatic repulsion hydrophilic interaction chromatography (ERLIC)-RP (pH 10)-RP (pH 2) [62]. Loroch et al. previously reported a 3D-LC system consisting of ERLIC–ERLIC-RP for the simultaneous analysis of proteome and phosphoproteome from one sample [63]. IEF-SCX-RP was also combined for analysis of human saliva proteome [64] and human plasma proteome [65].
HILIC separation was first introduced in 1990 [66] and has become popular over the last few years. It is appropriate to analyze polar compounds and has good complementary selectivity to RPLC. Furthermore, HILIC mobile phase is excellently compatible with that of RPLC, making it suitable to develop HILIC-RPLC 2D-LC systems with high orthogonality [44]. The success of some HILIC-RPLC 2D-LC platforms [32,33,34] resulted in their further utilization in 3D strategies. An SCX-HILIC-RP system was developed for phosphoproteome analysis in human cancer cells (HeLa and K562). The authors combined the strength of Ti4+-IMAC and SCX-HILIC separation to maximize the in-depth characterization of the cellular phosphoproteome. The 3D strategy showed beneficial when the sample amount was above 3 mg. It could identify 22,148 unique phosphopeptides and 4708 unique phosphoproteins in K562 cells. In HeLa cells, starting from 500 µg of samples, 11,980 unique phosphopeptides and 3424 phosphoproteins were identified by the 3D-LC system. Obviously, to achieve a high number of phosphopeptides and phosphoproteins in K562 cells, high sample consumption and a long analysis time were required [67]. Another combination, SEC-HILIC-RP, was used for human serum proteome analysis in patients with benign prostate hyperplasia. Different from other bottom-up studies, serum proteins were firstly pre-fractionated using SEC. After that, the proteins were subjected to dialysis exchange and in-solution digestion. The obtained peptides were then further fractionated using zwitterion–ion HILIC (ZIC-HILIC) prior to RPLC-MS/MS analysis [31]. A similar setup was used for proteomic analysis of Paracoccus denitrificans. With iTRAQ labeling, the total number of fractions was 32, and the number of protein identification was 2627, covering 52.3% of the putative proteome of the bacteria [68]. Setups and performance of some outstanding 3D-LC systems are summarized in Table 1.
Generally, offline 3D-LC systems suffer from sample loss due to nonspecific adsorption of samples to tube or other surfaces as well as the additional sample handling. They usually require a large amount of samples in the peptide level [69]. Therefore, a number of studies have integrated the fractionation step into the sample preparation procedure in the same device. These integrated devices could minimize the sample loss, enable a small amount of sample, and ensure high efficient digestion and fractionation. In 2006–2007, stop and go extraction tips (StageTips) consisting of stacking RP and SCX disks were developed for multidimensional fractionation, desalting, filtration, and concentration of peptides [71,72]. Recently, using this device, Kulak et al. reported a simple in-StageTip (iST) method that could enhance the throughput of peptide fractionation and identified 9667 proteins in HeLa cells [73]. Following, Adahi et al. identified more than 22,000 phosphopeptides using this StageTip [74]. As shown in Figure 1A, the StageTips device is an enclosed tip chamber with a membrane working as a filter and separation unit. In this device, SCX fractionation and C18 clean-up were combined. Obviously, these studies performed 2D-LC separation for proteomic analysis, not 3D-LC. However, this design can allow SCX-RP peptide fractionation by using appropriate eluents prior to PRLC-MS/MS analysis, making it a 3D-LC method. With a similar idea, Chen et al. previously developed a simple and integrated spintip-based protein digestion and 3D peptide fractionation technology (3D-SISPROT) with SAX and C18 membranes packed into one pipet tip. These systems allowed all the sample preparation steps to occur consecutively, including protein pre-concentration, reduction, alkylation, digestion, SAX-based fractionation, desalting, and high-pH RP fractionation. The third dimension was low-pH RPLC coupled with MS/MS analysis. 3D-SISPROT could readily identify more than 8000 proteins from 30 µg of cell lysates. As shown in Figure 1B, 3D-SISPROT firstly allowed SAX fractionation of the digested peptides using buffer solutions of different pH (pH 12, 6, and 2, respectively). The peptides from each SAX fraction were then captured by the C18 disk. They were fractionated using high-pH buffer solutions (5 mM ammonium formate (pH 10)) with a stepwise increasing gradient of ACN (3%, 6%, 9%, 15%, and 80% (v/v)). The obtained peptide samples were dried and reconstituted for the low-pH RPLC–MS/MS analysis [69]. Subsequently, this group further developed mixed-mode-SISPROT, in which, SCX and SAX beads were mixed with 1:1 ratio instead of the use of only SAX beads in 3D-SISPROT. In this design, protein digest was fractionated with SCX/SAX mixed-mode and then with high-pH RPLC prior to low-pH RPLC-MS/MS analysis. From 1 mL of serum, 862 proteins were identified with 12 fractions in 12 h of MS/MS analysis [70].

2.2. Online 3D-LC Systems

Some online 3D-LC systems have been developed with an attempt to reduce sample loss, labor intensity, and time. They are relatively sophisticated in instruments and typically limited in total sample capacity. In the early stage, after developing MudPIT as the first 2D-LC system, Yates’ group continued to design a 3-phase MudPIT column packed with RP-SCX-RP. It could be considered the first 3D-LC setup for proteomic analysis. However, during implementation, the first RP dimension served as a desalting step, and elution steps were carried out for a 2D separation (SCX-RP) [75]. Similarly, in 2005, another group constructed an RP-SCX-RP column for sample separation to discover yeast proteome [76]. However, with this column, a three-cycle method was carried out, including an RP gradient over 120 min, a salt step of 10 min, and an RP gradient of 120 min corresponding to RP1, SCX, and RP2 separation, respectively. When applying for proteomic analysis of Saccharomyces cerevisiae, this 3D-LC platform identified 3019 proteins, in which, approximately 1900 proteins consisted of at least 2 unique peptides [76]. Although no special setup was performed on LC separation, it was a factually online 3D-LC platform without offline pre-fractionation step. Wang et al. also developed an online 3D-LC platform with an RP-SCX biphasic column connected to an RP column prior to MS/MS analysis. This group, however, did not perform the first RP fractionation by adjusting eluents and the system was a 2D-LC platform rather than 3D-LC. Therefore, this system only quantified about 1000 proteins from 30 μg of human liver using 11 SCX fractions [77]. This system was later applied by Song et al. for phosphoproteome analysis; however, the implementation was still 2D-LC separation [78]. Until 2014, based on this setup, Xu et al. developed a combined offline and online 3D-LC system for proteome quantification of hepatocellular carcinoma tissues, which will be discussed in the following section [79].
Besides packing 3-phasic columns, some groups have developed online 3D-LC platforms by modifying setups of HPLC/UPLC systems. In 2011, one group reported an online 3D-LC platform consisting of RP (pH 10)-SAX-RP (pH 2) [80]. In this system, a SAX column was connected directly to the outlet of the first dimension RP column (Figure 2A). The third dimension column was set up using an additional six-port, two-position valve, which ensured the efficient capture of peptides. Online solvent adjustment was performed using 2 pumps. The first pump delivered different discrete eluents (with various ACN and KCl concentration), whereas the second binary pump eluted peptides from the third RPLC dimension column for MS/MS analysis. The system could generate from 19 up to 236 fractions for RPLC-MS/MS analysis depending on the steps in acetonitrile (first dimension) and salt concentrations (second dimension). The optimal achievement was the case of 101 fractions, in which the system identified 4004 proteins and 26,468 peptides from only 5 μg of yeast tryptic peptides. However, when the number of fractions was decreased to 51, there were negligible changes in the protein and peptide identification (only 5% reduction). The online fractionation strategies in this study provided large-scale proteome sequence coverage from only a few micrograms of tryptic peptides. However, the identification of approximately 4000 proteins was not dramatically high compared with recent studies when considering a total of 101 fractions and an analysis time of 202 h [80]. In another study, this group applied the same RP–SAX–RP approach to identify 12,739 phosphopeptides in 126.5 h with a peak capacity of over 3500 [81]. Continuously, by applying the same methodology, the authors developed DEep Efficient Peptide SEquencing and Quantification (DEEP SEQ) mass spectrometry platform to provide increased separation capacity, rapid sequencing speed and quantification of proteins in murine embryonic stem cells. From 20 RP-SAX fractions and combined with iTRAQ-labeling, DEEP SEQ could quantify 211,535 unique peptide sequences that mapped unambiguously to 11,352 proteins. The protein number spanned approximately 70% of the highly curated Swiss-Prot database, indicating the depth and scale of proteome coverage. The major drawback of this study was the long MS time of about 24 days (for triplicate analysis of 20 fractions, each fraction about 9.7 h) [82].
In 2015, another online 3D-LC system consisting of RP (pH 10)-SCX-RP (pH 2) was developed. Three different pumps were used to deliver eluents, and column flow switching was carried out using two ten-port switching valves (Figure 2B). The first pump (pH 10 gradient pump) separated peptides to different high-pH RPLC fractions. Each fraction from the first dimension was collected using a mixing loop and then transferred to one SCX-RP column. The RP portion was used as a trapping column prior to low-pH RPLC-MS/MS analysis. The second pump (pH 2 loading pump) introduced a salt pulse (low or high) to elute peptides from the SCX portion to the RP portion. The peptides were then eluted with a low-pH gradient solvent delivered by the third pump (pH 2 gradient pump). Two SCX-RP columns were used, allowing the simultaneous performance of pumps 2 and 3 as follows: analysis of RP1/SCX1 fraction and elution of RP2/SCX1 fraction, analysis of RP2/SCX1 fraction and elution of RP1/SCX2 fraction, analysis of RP1/SCX2 fraction and elution of RP2/SCX2 fraction, analysis of RP2/SCX2 fraction and elution of RP3/SCX1 fraction. It continued until the last fraction was analyzed. In rat pheochromocytoma PC12 cell, this online 3D-LC system could identify 6345 proteins and 97,309 unique peptides with 12 fractions in 24 h. This platform was amenable to high-throughput analyses with almost no idle time in sample fractionation, trapping, and desalting [83].
Overall, online 3D-LC systems for proteomic applications have been developed for many years. At the early stage, packing 2- and 3-phasic columns were mostly used [75,76,77,78]. Later, more sophisticated systems were designed to enhance their performance [80,81,82,83]. Some platforms were proven to be powerful for in-depth proteome analyses despite the fact that they were hard to be set up without well-trained skills. The performance of some online 3D-LC systems is outlined in Table 2.

2.3. Combined Offline-Online 3D-LC Systems

A 3D-LC strategy can be performed using a mixed online and offline system. The sample is either pre-fractionated with the first dimension prior to an online 2D-LC separation or fractionated with an online 2D-LC platform and then separated with the third dimension coupled with MS/MS analysis. Utilizing the former approach, a simple RP-SCX-RP 3D-LC was previously developed by Xu et al. (Figure 3A). This group firstly performed on-column sample purification, stable isotope dimethyl labeling, and high-pH RP pre-fractionation using polystyrene-divinylbenzene beads-packed solid-phase extraction column. Three fractions were collected and subsequently subjected to online SCX–RP 2D-LC-MS/MS analysis [79]. The setup of the online SCX-RP 2D-LC was previously described [77]. Each high-pH RP fraction was loaded onto the RP segment of the RP-SCX biphasic trap column. The peptides were transferred to the SCX segment with a 90 min RP gradient and then to the C18 separation column with a series of 12 stepwise elutions with different salt concentrations at low pH (pH 2.7). After each salt step, a 200 min binary low-pH RP gradient was applied to separate the peptides prior to MS/MS analysis. With 36 RP-SCX fractions and a total MS/MS analysis time of 124 h, this 3D-LC system was successfully applied to identify more than 2700 proteins, access the differential proteome expression of hepatocellular carcinoma tissues and normal liver tissues, and thereby discover dysregulated proteins during the hepatocarcinogenesis process [79].
Recently, a different 3D-LC setup was presented, which combined online SCX-RP fractionation and CZE-MS/MS analysis (Figure 3B). The peptides loaded onto the SCX column were eluted with three different concentrations of ammonium acetate (150, 350, and 890 mM). After each salt step, the eluted peptides captured on the RPLC column were further separated with low-pH RPLC gradient solvents to generate 20 fractions. Subsequently, 60 SCX-RPLC fractions were subjected to CZE-MS/MS analysis, which identified about 8200 protein groups and 65,000 unique peptides from a mouse brain proteome digest. This is one of the rare studies that do not use low-pH RPLC as the final fractionation prior to MS/MS analysis [51]. Table 3 summarizes major features of these two combined 3D-LC platforms.

2.4. Comparison of Offline and Online Setups

We have discussed the setups and performance of various online, offline, and combined 3D-LC systems, from which, some advantages and limitations of each strategy can be withdrawn. Obviously, offline systems are simple in design and therefore, easy to transfer to other laboratories. Online platforms usually require sophisticated setups and well-trained persons to operate, and therefore they are difficult for technology transfer. Conducting 3D-LC systems in an offline manner can allow a high amount of loading sample. However, this is also one of their drawbacks, since they are not suitable for samples with a low amount, particularly clinical samples. In contrast, online platforms only require a small amount of protein digest (several to 100 μg), making them ideal for some cases when the sample amount is limited [84]. Apparently, if we attempt to increase the numbers of peptide and protein identification through increasing sample amount and fraction number, an offline strategy is the appropriate one, rather than an online strategy. Also, offline fractionation is highly flexible since each dimensional separation can be carried out separately for optimization by varying buffer and elution conditions. In each fractionation process, nonconsecutive fractions can be pooled to reduce the total fraction number depending on the sample complexity [83,84,85]. When the fractionation step is carefully optimized, it can offer critical advantages in terms of the number of fractions reduction and analysis time. One of the major limitations of offline 3D-LC platforms is a high risk of sample loss and contamination, as a result of high-labor intensity with many sample handling steps. The online systems are usually fully automated; samples are continuously delivered between consecutive dimensions through the use of switching valves, additional pumps and trapping columns. The sample loss is thereby considerably low. Online strategies sometimes decrease the overall time from sample preparation to analysis [19,42]. Thus, each strategy has some advantages and drawbacks. Several features in these two strategies comparison are listed in Table 4. Recently, with the development of some integrated devices as has been discussed, offline 3D-LC strategies could overcome their major limitations: sample loss and large sample amount requirement [69,70,71,72,73,74]. These devices, therefore, make the recent offline 3D-LC approaches more potent and applicable to clinical samples. Some combined 3D-LC systems have been developed as discussed above. They might include some advantages and limitations of both offline and online systems. Since there are not many existing combined 3D-LC platforms, it is not easy to compare them with other offline and online systems.

3. The Power of 3D-LC Compared to 1D and 2D-LC

Performance comparisons among 3D-LC, 2D-LC, and 1D-LC systems have been reported in some studies, which are summarized in Table 5. In the 3D-SISPROT system, the efficacy of 3D-LC was indicated by comparison of performance among three modes: 1D-, 2D-, and 3D-SISPROT. In 1D-SISPROT, the cell lysates (HEK 293T) were digested and then analyzed by the low-pH RPLC–MS/MS, whereas in 2D-SISPROT, the cell lysates were digested and fractionated on the SAX disk, followed by the low-pH RPLC–MS/MS analysis. The 3D-SISPROT included SAX fractionation, high-pH RPLC fractionation, and low-pH RPLC–MS/MS analysis. As a result, 4275 proteins and 19,768 unique peptides were identified in the 1D-SISPROT mode with only 1.4 h of MS time. Those numbers increased to 5380 proteins and 34,912 unique peptides in the 2D-SISPROT mode with 3 SAX fractions. Taking advantage of the 3D separation strategy, the 3D-SISPROT mode identified 8222 proteins and 74,432 unique peptides with 11 SAX-RP fractions in the MS time of 20.4 h. Thus, 3D-SISPROT intensively increased the numbers of identified proteins and unique peptides in comparison with 2D- and 1D-SISPROT [69]. A previous study also found similar results when comparing the performance of 1D (RP), 2D (RP-RP), and 3D (RP-RP-RP) [61]. Compared with the 2D-LC, the 3D-LC procedure increased the identification of protein and peptide 1.6- and 2.3-fold, respectively.
Zhou et al. compared the efficacy of 1D, 2D, and 3D systems for the identification of phosphoproteins in HeLa and K562 cells. The author evaluated those strategies in two cases: (i) sample amounts are limited (HeLa cells) and (ii) sample amounts are not limited (K562 cells). In the first case, 3726 unique phosphopeptides originating from 1570 phosphoproteins were identified using 1D-LC. The 2D-LC increased the numbers of phosphopeptides and phosphoproteins to 16,637 and 3891, respectively as HILIC fractionation was utilized. Surprisingly, the overall identifications of phosphopeptides and phosphoproteins in the 3D-LC strategy were 11,980 and 3424, respectively, lower than those obtained from the 2D-LC strategy when using the same starting amount of material. It could be due to the greater total loss of the 3D-LC strategy compared to the 2D-LC strategy. In this case, the sample amount was within the capability of the 2D-LC system; therefore, the use of the 3D-LC was not essential. However, in the second case, when sample amounts were unlimited, the efficacy of the 3D strategy was proven. When the sample amount was increased from 1.5 to 3 mg, the 2D-LC system only provided a 20% increase in the number of phosphopeptides (from approximately 14,000 to nearly 17,000). The dynamic range and intrinsic complexity within each HILIC fraction limited the performance of the 2D-LC system despite the sufficient sensitivity of the final LC−MS step. In the 3D strategy, with 66 SCX-HILIC fractions, the number of phosphopeptides and phosphoproteins in increased considerably to 22,148 and 4708, respectively. Thus, a 3D-LC system is not always superior to a 2D-LC system. When the sample amount is small, the selection of a 2D- or 3D-LC strategy should be carefully considered [67].
In the study of Law et al., the 3D RP–SCX–RP platform outperformed the 2D RP–RP platform in terms of the numbers of identified peptide and protein [83]. When operating the 3D-LC platform, 3114 proteins and 25,792 unique peptides were identified in a single run, higher than those of the 2D-LC platform (2358 proteins and 13,573 unique peptides) and comparable with the data obtained from triplicate runs of the 2D-LC platform (3170 proteins and 23,806 unique peptides). In another study aiming at the identification of human urinary proteins, data obtained from two 3D systems (GELFrEE-RP-RP and LPIEF-RP-RP) were combined. In total, they showed more than 6000 identified proteins, 2-time higher than that of the RP-RP system [60]. A recent study revealed that a 3D-LC (SCX-RP-CZE) produced comparable numbers of protein groups and unique peptides with a state-of-the-art 2D-LC (RP-RP) from the mouse brain proteome digest using comparable MS/MS analysis time (8200 vs. 8900 protein groups, 65,000 vs. 70,000 unique peptides, 70 h vs. 60 h). This study proved for the first time that CZE-MS/MS could approach comparable performance to the cutting-edge 2D-LC-MS/MS for deep proteomic sequencing. Obviously, the 3D-LC did not show superiority compared to the 2D-LC. In this case, the 2D-LC, due to its simple setup and implementation, would be preferred. However, since the separation mechanisms of CZE and RPLC were different, combining those two methods could improve the number of protein groups and unique peptides by about 10% and 40%, respectively, compared with the 2D-LC alone [51]. In the above-mentioned studies, the number of fractions in 3D-LC was always higher than that in 2D-LC. However, a previous study showed that even when the fraction numbers were similar between 2D-LC and 3D-LC, the later still provided more protein and peptide identification. In this study, the online RP-SAX-RP platform could identify 46% and 31% more peptides and proteins, respectively, as compared to the online RP-RP [80].

4. Author’s Outlook and Concluding Remarks

Significant improvements have been obtained in proteome analysis using 2D-LC. It remarkably provides a higher peak capacity than 1D-LC. However, the resolution might still be limited in the cases of highly complex samples [43]. Therefore, many studies have been conducted to achieve deeper proteome coverage. By adding one more separation stage, some 3D-LC systems have been developed with an attempt to reduce the sample complexity further, increase the peak capacity even more, and improve the efficiency of the LC-MS/MS analysis. The 3D-LC separation requires the selection of three separate dimensions that are highly independent and mutually orthogonal. Also, the mobile phases need to be compatible, particularly with online systems [86]. Although it is a difficult task, various 3D-LC strategies have been developed and widely used. As discussed above, different combinations of LC modes were available in 3D-LC systems. The establishment of a 3D-LC platform depends on some factors, such as experiment type, sample type, and sample amount. Online and offline systems have their own advantages and limitations. Generally, when sample quantity is limiting, one can choose online strategies or use offline platforms with integrated devices.
It should be noted that the utilization of a 3D-LC system for proteomic analysis is not always the best choice. A 3D-LC system may not be superior to a 2D-LC system when the sample amount is small [67]. In addition, the peak capacity of 3D-LC may not be improved significantly compared to 2D-LC [86]. Sometimes, the selection of three LC modes in 3D-LC does not result in a better performance in comparison with a conventional 2D-LC [51]. In some cases, a 2D-LC is well performed and able to generate satisfactory results. For example, in a recent study, when high-pH RP fractionation and low-pH RPLC-MS/MS analysis were used, approximately 584,000 unique peptides and 14,200 protein isoforms were identified from HeLa cells [87]. Generally, 3D-LC systems suffer from sample loss, an increase in time and sample consumptions. Sample loss is one of the major drawbacks when performing 3D-LC [70]. As a result, 3D-LC methods often require a large amount of sample. It is particularly prominent in offline systems with the use of several hundred micrograms [61] to microgram [68] of peptide sample. However, the development of integrated devices has intensely reduced the sample amount. For example, the 3D-LC method with mixed-mode-SISPROT can be performed with ~ 60 µg of depleted plasma [70]. One can also choose to carry out online 3D-LC for in-depth proteomic analysis in case the sample amount is limited. The sample amount can be reduced to 100–200 µg [76,83] or even less than 100 µg [80,82]. Besides, one of the unavoidable disadvantages of 3D-LC is the long analysis time. As shown in Table 5, the analysis time for 3D-LC is longer than that for 2D-LC at least 3–6 times [61,67,69] or even 18 times [60]. However, there was a study, in which the 3D-LC method required a shorter analysis time compared to the 2D-LC method (74 h vs. 80 h) but still provided higher numbers of protein and peptide identification [80]. Overall, the increase in analysis time for 3D-LC is an inevitable result arising from the increase in the number of fractions. However, depending on each study, we should decide an appropriate fraction number that could be beneficial to the in-depth proteomic data, whereas the analysis time is not so long [51]. In some cases, increasing to a higher fraction number (i.e., longer analysis time) only gains a little increase in peptide and protein identification [80].
In addition, there are two particularly important issues when 3D-LC strategies are applied for label-free quantitation of proteomic samples. The first one is a deterioration of chromatographic profiles for the abundant peptides that may occur due to the increase in peptide load. The second one is an increase in the proportion of unwanted peptide modification due to fractions handling [61]. Another disadvantage with 3D-LC is that a single peak could be split into multiple fractions, making it difficult in a quantitative analysis [6]. For example, when performing DEEP SEQ MS, about 11.5% of all detected peptides span in more than one fraction [82]. It results in difficulties when utilizing label-free quantification in 3D-LC strategies. Moreover, 3D-LC systems may suffer low reproducibility in quantification. However, these issues have been solved in recent studies using different labeling methods. For example, using the pseudo-triplex dimethyl isotope labeling approach, one can obtain two replicated quantification results in just one experiment [78,79]. Loroch et al. used a 2-plex stable isotope labeling by amino acids in cell culture (SILAC) to combine two biological replicates in one experiment and conduct a 3D-LC strategy [63]. Hence, labeling methods can allow the implementation of two or more samples under completely identical conditions, which therefore improves the reproducibility. Other labeling methods such as tandem mass tags (TMT), isobaric tags for relative and absolute quantitation (iTRAQ) can even be used for a quantitative comparison of up to 8 or 10 samples [6]. Thus, the implementation of a 3D-LC strategy usually requires more time and effort and should be compensated by significantly improved output. Furthermore, recent advances in MS have sometimes resulted in satisfactory outcome without MD-LC, such as the implementation of online parallel accumulation–serial fragmentation (PASEF) could identify about 2100 proteins from only 10 ng HeLa digest in 30 min and quantify 5575 protein groups in 2 h LC-MS/MS time across four injections [88]. When the analytical question is to focus on quantitative results, the in-depth proteomic analysis with MD-LC may not be necessary. In this case, one might perform a different strategy, such as sequential window acquisition of all theoretical spectra (SWATH) MS [89] or data-independent acquisition (DIA) MS [90].
Some studies have performed quantitative proteomics with MD-LC strategies to achieve a deep coverage proteome quantification [6,42,44]. It is of great benefit for clinical applications, particularly for the discovery of biomarkers [91]. It was reported that a 3D-LC strategy combined with iTRAQ-labeling could quantify more than 200,000 unique peptides [82]. Ficarro et al. used iTRAQ 4-plex reagent to label peptides from four different samples. After mixing, labeled phosphopeptides were enriched and then subjected to a 3D-LC MS/MS analysis (67 fractions) [81]. Furthermore, in another quantitative proteomic study, 8-plex iTRAQ reagent allowed the parallel analysis of eight samples (4 conditions × 2 replicates) in one experiment [68]. A recent study used 4-plex iTRAQ reagent to label 2 independent biological replicates of peptide samples from a pair of a tumor and an adjacent normal tissue [92]. Using these labeling methods, 3D-LC strategies can enable peptide and protein quantification with high accuracy and reproducibility.
In conclusion, various MD-LC systems have been described so far for peptide separation in proteomic studies. The selection of the most suitable one for an experiment depends on many factors, such as the analytical question, available equipment, sample type, sample amount, available analysis time, and experience as well as skills of the operators. In each case, we have to answer many questions:
Should we perform an MD-LC method? If yes, is a 2D-LC or a 3D-LC method suitable?
Which LC modes should be combined?
If it is a 3D-LC system, should it be offline, online, or combined?
Up to date, the outstanding performance of 3D-LC is undeniable. We believe that 3D-LC systems will be continuously developed, improved, and applied in the future. The development of 3D-LC combined with major improvements in the sensitivity and the resolution of MS/MS analysis will enable increasingly wider proteome identification. Basic 2D-LC combinations such as SCX-RP and RP-RP will be fundamental for future 3D-LC systems. In addition, other LC modes, including HILIC, ERLIC, mixed SCX-SAX will be continuously combined and investigated. The options of 3D-LC strategies will therefore expand. Offline and online 3D-LC systems will be developed simultaneously since they possess their unique advantages. Combined systems may still be developed, taking advantage of the state-of-the-rat 2D-LC strategies. Finally, integrated devices that enable many steps in sample preparation and fractionation will continuously demonstrate their utility and be incorporated in many 3D-LC platforms. Particularly, with the wide-spreading of automated sample handling platforms, these devices will be the future of high throughput sample preparation for 3D-LC.

Author Contributions

H.L. conceptualized and supervised the project; V.-A.D. and J.-M.P. wrote the manuscript. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by a National Research Foundation of Korea (NRF) grant, funded by the Korean government (MSIT) (No. NRF-2017M3D9A1073784, NRF-2016M1A5A1027461).

Conflicts of Interest

The authors declare no conflict of interest.

Abbreviations

PTMsPost-translational modifications
MDMultidimensional
2DTwo-dimensional
3DThree-dimensional
MudPITMultidimensional protein identification technology
SCXStrong cation exchange
RPLCReversed phase liquid chromatography
SAXStrong anion exchange
SECSize exclusion chromatography
HILICHydrophilic interaction chromatography
CZECapillary zone electrophoresis
GELFrEEGel-eluted liquid fraction entrapment electrophoresis
LPIEFLiquid-phase isoelectric focusing
ERLICElectrostatic repulsion hydrophilic interaction chromatography
ZICZwitterion–ion
StageTipsStop and go extraction tips
iSTin-StageTip
3D-SISPROT3D peptide fractionation technology
SILACStable isotope labeling by amino acids in cell culture
TMTTandem mass tags
iTRAQIsobaric tags for relative and absolute quantitation
DEEP SEQDEep Efficient Peptide SEquencing and Quantification
PASEFParallel accumulation–serial fragmentation
SWATHSequential window acquisition of all theoretical spectra
DIAData-independent acquisition

References

  1. Tyers, M.; Mann, M. From genomics to proteomics. Nature 2003, 422, 193–197. [Google Scholar] [CrossRef]
  2. Larance, M.; Lamond, A.I. Multidimensional proteomics for cell biology. Nat. Rev. Mol. Cell Biol. 2015, 16, 269–280. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  3. Youngblood, H.; Robinson, R.; Sharma, A.; Sharma, S. Proteomic Biomarkers of Retinal Inflammation in Diabetic Retinopathy. Int. J. Mol. Sci. 2019, 20, 4755. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  4. Kalita-de Croft, P.; Straube, J.; Lim, M.; Al-Ejeh, F.; Lakhani, S.R.; Saunus, J.M. Proteomic Analysis of the Breast Cancer Brain Metastasis Microenvironment. Int. J. Mol. Sci. 2019, 20, 2524. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  5. Koren, S.A.; Gillett, D.A.; D’Alton, S.V.; Hamm, M.J.; Abisambra, J.F. Proteomic Techniques to Examine Neuronal Translational Dynamics. Int. J. Mol. Sci. 2019, 20, 3524. [Google Scholar] [CrossRef] [Green Version]
  6. Wu, Q.; Yuan, H.; Zhang, L.; Zhang, Y. Recent advances on multidimensional liquid chromatography–mass spectrometry for proteomics: From qualitative to quantitative analysis—A review. Anal. Chim. Acta 2012, 731, 1–10. [Google Scholar] [CrossRef]
  7. Toby, T.K.; Fornelli, L.; Kelleher, N.L. Progress in Top-Down Proteomics and the Analysis of Proteoforms. Annu. Rev. Anal. Chem. 2016, 9, 499–519. [Google Scholar] [CrossRef] [Green Version]
  8. Cai, W.; Tucholski, T.M.; Gregorich, Z.R.; Ge, Y. Top-down Proteomics: Technology Advancements and Applications to Heart Diseases. Expert Rev. Proteom. 2016, 13, 717–730. [Google Scholar] [CrossRef] [Green Version]
  9. Gregorich, Z.R.; Ge, Y. Top-down proteomics in health and disease: Challenges and opportunities. Proteomics 2014, 14, 1195–1210. [Google Scholar] [CrossRef]
  10. Gillet, L.C.; Leitner, A.; Aebersold, R. Mass Spectrometry Applied to Bottom-Up Proteomics: Entering the High-Throughput Era for Hypothesis Testing. Annu. Rev. Anal. Chem. 2016, 9, 449–472. [Google Scholar] [CrossRef]
  11. Mayne, J.; Ning, Z.; Zhang, X.; Starr, A.E.; Chen, R.; Deeke, S.; Chiang, C.-K.; Xu, B.; Wen, M.; Cheng, K.; et al. Bottom-Up Proteomics (2013–2015): Keeping up in the Era of Systems Biology. Anal. Chem. 2016, 88, 95–121. [Google Scholar] [CrossRef] [PubMed]
  12. Blein-Nicolas, M.; Zivy, M. Thousand and one ways to quantify and compare protein abundances in label-free bottom-up proteomics. Biochim. Biophys. Acta (BBA)-Proteins Proteom. 2016, 1864, 883–895. [Google Scholar] [CrossRef] [PubMed]
  13. Yates, J.R.; Ruse, C.I.; Nakorchevsky, A. Proteomics by Mass Spectrometry: Approaches, Advances, and Applications. Annu. Rev. Biomed. Eng. 2009, 11, 49–79. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  14. Riley, N.M.; Coon, J.J. The Role of Electron Transfer Dissociation in Modern Proteomics. Anal. Chem. 2018, 90, 40–64. [Google Scholar] [CrossRef]
  15. Andrews, G.L.; Simons, B.L.; Young, J.B.; Hawkridge, A.M.; Muddiman, D.C. Performance Characteristics of a New Hybrid Quadrupole Time-of-Flight Tandem Mass Spectrometer (TripleTOF 5600). Anal. Chem. 2011, 83, 5442–5446. [Google Scholar] [CrossRef] [Green Version]
  16. Muntel, J.; Xuan, Y.; Berger, S.T.; Reiter, L.; Bachur, R.; Kentsis, A.; Steen, H. Advancing Urinary Protein Biomarker Discovery by Data-Independent Acquisition on a Quadrupole-Orbitrap Mass Spectrometer. J. Proteome Res. 2015, 14, 4752–4762. [Google Scholar] [CrossRef] [Green Version]
  17. Bayat, P.; Lesage, D.; Cole, R.B. Low-energy collision-induced dissociation (low-energy CID), collision-induced dissociation (CID), and higher energy collision dissociation (HCD) mass spectrometry for structural elucidation of saccharides and clarification of their dissolution mechanism in DMAc/LiCl. J. Mass Spectrom. 2018, 53, 705–716. [Google Scholar] [CrossRef]
  18. Di Palma, S.; Hennrich, M.L.; Heck, A.J.R.; Mohammed, S. Recent advances in peptide separation by multidimensional liquid chromatography for proteome analysis. J. Proteom. 2012, 75, 3791–3813. [Google Scholar] [CrossRef]
  19. Ranjbar, L.; Foley, J.P.; Breadmore, M.C. Multidimensional liquid-phase separations combining both chromatography and electrophoresis—A review. Anal. Chim. Acta 2017, 950, 7–31. [Google Scholar] [CrossRef]
  20. Vivó-Truyols, G.; van der Wal, S.; Schoenmakers, P.J. Comprehensive Study on the Optimization of Online Two-Dimensional Liquid Chromatographic Systems Considering Losses in Theoretical Peak Capacity in First- and Second-Dimensions: A Pareto-Optimality Approach. Anal. Chem. 2010, 82, 8525–8536. [Google Scholar] [CrossRef]
  21. Li, X.; Stoll, D.R.; Carr, P.W. Equation for Peak Capacity Estimation in Two-Dimensional Liquid Chromatography. Anal. Chem. 2009, 81, 845–850. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  22. Washburn, M.P.; Wolters, D.; Yates, J.R. Large-scale analysis of the yeast proteome by multidimensional protein identification technology. Nat. Biotechnol. 2001, 19, 242–247. [Google Scholar] [CrossRef] [PubMed]
  23. Tao, D.; Qiao, X.; Sun, L.; Hou, C.; Gao, L.; Zhang, L.; Shan, Y.; Liang, Z.; Zhang, Y. Development of a Highly Efficient 2-D System with a Serially Coupled Long Column and Its Application in Identification of Rat Brain Integral Membrane Proteins with Ionic Liquids-Assisted Solubilization and Digestion. J. Proteome Res. 2011, 10, 732–738. [Google Scholar] [CrossRef] [PubMed]
  24. Millioni, R.; Tolin, S.; Puricelli, L.; Sbrignadello, S.; Fadini, G.P.; Tessari, P.; Arrigoni, G. High Abundance Proteins Depletion vs Low Abundance Proteins Enrichment: Comparison of Methods to Reduce the Plasma Proteome Complexity. PLoS ONE 2011, 6, e19603. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  25. Zhu, M.-Z.; Li, N.; Wang, Y.-T.; Liu, N.; Guo, M.-Q.; Sun, B.-q.; Zhou, H.; Liu, L.; Wu, J.-L. Acid/Salt/pH Gradient Improved Resolution and Sensitivity in Proteomics Study Using 2D SCX-RP LC–MS. J. Proteome Res. 2017, 16, 3470–3475. [Google Scholar] [CrossRef] [PubMed]
  26. Wang, H.; Sun, S.; Zhang, Y.; Chen, S.; Liu, P.; Liu, B. An off-line high pH reversed-phase fractionation and nano-liquid chromatography–mass spectrometry method for global proteomic profiling of cell lines. J. Chromatogr. B 2015, 974, 90–95. [Google Scholar] [CrossRef] [PubMed]
  27. Vonk, R.J.; Gargano, A.F.G.; Davydova, E.; Dekker, H.L.; Eeltink, S.; de Koning, L.J.; Schoenmakers, P.J. Comprehensive Two-Dimensional Liquid Chromatography with Stationary-Phase-Assisted Modulation Coupled to High-Resolution Mass Spectrometry Applied to Proteome Analysis of Saccharomyces cerevisiae. Anal. Chem. 2015, 87, 5387–5394. [Google Scholar] [CrossRef]
  28. Chen, W.; Wang, S.; Adhikari, S.; Deng, Z.; Wang, L.; Chen, L.; Ke, M.; Yang, P.; Tian, R. Simple and Integrated Spintip-Based Technology Applied for Deep Proteome Profiling. Anal. Chem. 2016, 88, 4864–4871. [Google Scholar] [CrossRef]
  29. Zhou, H.; Hou, W.; Lambert, J.-P.; Tian, R.; Figeys, D. Analysis of low-abundance proteins using the proteomic reactor with pH fractionation. Talanta 2010, 80, 1526–1531. [Google Scholar] [CrossRef]
  30. Lee, H.-J.; Na, K.; Kwon, M.-S.; Park, T.; Kim, K.S.; Kim, H.; Paik, Y.-K. A new versatile peptide-based size exclusion chromatography platform for global profiling and quantitation of candidate biomarkers in hepatocellular carcinoma specimens. Proteomics 2011, 11, 1976–1984. [Google Scholar] [CrossRef]
  31. Garbis, S.D.; Roumeliotis, T.I.; Tyritzis, S.I.; Zorpas, K.M.; Pavlakis, K.; Constantinides, C.A. A Novel Multidimensional Protein Identification Technology Approach Combining Protein Size Exclusion Prefractionation, Peptide Zwitterion−Ion Hydrophilic Interaction Chromatography, and Nano-Ultraperformance RP Chromatography/nESI-MS2 for the in-Depth Analysis of the Serum Proteome and Phosphoproteome: Application to Clinical Sera Derived from Humans with Benign Prostate Hyperplasia. Anal. Chem. 2011, 83, 708–718. [Google Scholar] [CrossRef] [PubMed]
  32. Di Palma, S.; Stange, D.; van de Wetering, M.; Clevers, H.; Heck, A.J.R.; Mohammed, S. Highly Sensitive Proteome Analysis of FACS-Sorted Adult Colon Stem Cells. J. Proteome Res. 2011, 10, 3814–3819. [Google Scholar] [CrossRef] [PubMed]
  33. Di Palma, S.; Boersema, P.J.; Heck, A.J.R.; Mohammed, S. Zwitterionic Hydrophilic Interaction Liquid Chromatography (ZIC-HILIC and ZIC-cHILIC) Provide High Resolution Separation and Increase Sensitivity in Proteome Analysis. Anal. Chem. 2011, 83, 3440–3447. [Google Scholar] [CrossRef] [PubMed]
  34. Cao, J.-L.; Wang, S.-S.; Hu, H.; He, C.-W.; Wan, J.-B.; Su, H.-X.; Wang, Y.-T.; Li, P. Online comprehensive two-dimensional hydrophilic interaction chromatography×reversed-phase liquid chromatography coupled with hybrid linear ion trap Orbitrap mass spectrometry for the analysis of phenolic acids in Salvia miltiorrhiza. J. Chromatogr. A 2018, 1536, 216–227. [Google Scholar] [CrossRef] [PubMed]
  35. Ye, L.; Wang, X.; Han, J.; Gao, F.; Xu, L.; Xiao, Z.; Bai, P.; Wang, Q.; Zhang, B. Two dimensional separations of human urinary protein digest using a droplet-interfaced platform. Anal. Chim. Acta 2015, 863, 86–94. [Google Scholar] [CrossRef] [PubMed]
  36. Song, C.; Ye, M.; Han, G.; Jiang, X.; Wang, F.; Yu, Z.; Chen, R.; Zou, H. Reversed-Phase-Reversed-Phase Liquid Chromatography Approach with High Orthogonality for Multidimensional Separation of Phosphopeptides. Anal. Chem. 2010, 82, 53–56. [Google Scholar] [CrossRef]
  37. Donato, P.; Cacciola, F.; Sommella, E.; Fanali, C.; Dugo, L.; Dachà, M.; Campiglia, P.; Novellino, E.; Dugo, P.; Mondello, L. Online Comprehensive RPLC × RPLC with Mass Spectrometry Detection for the Analysis of Proteome Samples. Anal. Chem. 2011, 83, 2485–2491. [Google Scholar] [CrossRef]
  38. Dou, M.; Tsai, C.-F.; Piehowski, P.D.; Wang, Y.; Fillmore, T.L.; Zhao, R.; Moore, R.J.; Zhang, P.; Qian, W.-J.; Smith, R.D.; et al. Automated Nanoflow Two-Dimensional Reversed-Phase Liquid Chromatography System Enables In-Depth Proteome and Phosphoproteome Profiling of Nanoscale Samples. Anal. Chem. 2019, 91, 9707–9715. [Google Scholar] [CrossRef]
  39. Dou, M.; Zhu, Y.; Liyu, A.; Liang, Y.; Chen, J.; Piehowski, P.D.; Xu, K.; Zhao, R.; Moore, R.J.; Atkinson, M.A.; et al. Nanowell-mediated two-dimensional liquid chromatography enables deep proteome profiling of <1000 mammalian cells. Chem. Sci. 2018, 9, 6944–6951. [Google Scholar] [CrossRef] [Green Version]
  40. Lee, H.; Mun, D.-G.; So, J.E.; Bae, J.; Kim, H.; Masselon, C.; Lee, S.-W. Efficient Exploitation of Separation Space in Two-Dimensional Liquid Chromatography System for Comprehensive and Efficient Proteomic Analyses. Anal. Chem. 2016, 88, 11734–11741. [Google Scholar] [CrossRef]
  41. Horvatovich, P.; Hoekman, B.; Govorukhina, N.; Bischoff, R. Multidimensional chromatography coupled to mass spectrometry in analysing complex proteomics samples. J. Sep. Sci. 2010, 33, 1421–1437. [Google Scholar] [CrossRef] [PubMed]
  42. Yuan, H.; Jiang, B.; Zhao, B.; Zhang, L.; Zhang, Y. Recent Advances in Multidimensional Separation for Proteome Analysis. Anal. Chem. 2019, 91, 264–276. [Google Scholar] [CrossRef] [PubMed]
  43. Malerod, H.; Lundanes, E.; Greibrokk, T. Recent advances in on-line multidimensional liquid chromatography. Anal. Methods 2010, 2, 110–122. [Google Scholar] [CrossRef]
  44. Zhang, X.; Fang, A.; Riley, C.P.; Wang, M.; Regnier, F.E.; Buck, C. Multi-dimensional liquid chromatography in proteomics—A review. Anal. Chim. Acta 2010, 664, 101–113. [Google Scholar] [CrossRef] [Green Version]
  45. van de Meent, M.H.M.; de Jong, G.J. Novel liquid-chromatography columns for proteomics research. TrAC Trends Anal. Chem. 2011, 30, 1809–1818. [Google Scholar] [CrossRef]
  46. Makarov, A.; Scigelova, M. Coupling liquid chromatography to Orbitrap mass spectrometry. J. Chromatogr. A 2010, 1217, 3938–3945. [Google Scholar] [CrossRef] [Green Version]
  47. Tao, D.; Zhang, L.; Shan, Y.; Liang, Z.; Zhang, Y. Recent advances in micro-scale and nano-scale high-performance liquid-phase chromatography for proteome research. Anal. Bioanal. Chem. 2011, 399, 229–241. [Google Scholar] [CrossRef]
  48. Motoyama, A.; Xu, T.; Ruse, C.I.; Wohlschlegel, J.A.; Yates, J.R. Anion and Cation Mixed-Bed Ion Exchange for Enhanced Multidimensional Separations of Peptides and Phosphopeptides. Anal. Chem. 2007, 79, 3623–3634. [Google Scholar] [CrossRef] [Green Version]
  49. Wolters, D.A.; Washburn, M.P.; Yates, J.R. An Automated Multidimensional Protein Identification Technology for Shotgun Proteomics. Anal. Chem. 2001, 73, 5683–5690. [Google Scholar] [CrossRef]
  50. Dai, J.; Jin, W.-H.; Sheng, Q.-H.; Shieh, C.-H.; Wu, J.-R.; Zeng, R. Protein Phosphorylation and Expression Profiling by Yin-Yang Multidimensional Liquid Chromatography (Yin-Yang MDLC) Mass Spectrometry. J. Proteome Res. 2007, 6, 250–262. [Google Scholar] [CrossRef] [Green Version]
  51. Chen, D.; Shen, X.; Sun, L. Strong cation exchange-reversed phase liquid chromatography-capillary zone electrophoresis-tandem mass spectrometry platform with high peak capacity for deep bottom-up proteomics. Anal. Chim. Acta 2018, 1012, 1–9. [Google Scholar] [CrossRef] [PubMed]
  52. Lorne Burke, T.W.; Mant, C.T.; Black, J.A.; Hodges, R.S. Strong cation-exchange high-performance liquid chromatography of peptides: Effect of non-specific hydrophobic interactions and linearization of peptide retention behaviour. J. Chromatogr. A 1989, 476, 377–389. [Google Scholar] [CrossRef]
  53. Wang, Z.; Ma, H.; Smith, K.; Wu, S. Two-dimensional separation using high-pH and low-pH reversed phase liquid chromatography for top-down proteomics. Int. J. Mass Spectrom. 2018, 427, 43–51. [Google Scholar] [CrossRef] [PubMed]
  54. Hood, B.L.; Zhou, M.; Chan, K.C.; Lucas, D.A.; Kim, G.J.; Issaq, H.J.; Veenstra, T.D.; Conrads, T.P. Investigation of the Mouse Serum Proteome. J. Proteome Res. 2005, 4, 1561–1568. [Google Scholar] [CrossRef] [PubMed]
  55. Zhang, J.; Xu, X.; Gao, M.; Yang, P.; Zhang, X. Comparison of 2-D LC and 3-D LC with post- and pre-tryptic-digestion SEC fractionation for proteome analysis of normal human liver tissue. Proteomics 2007, 7, 500–512. [Google Scholar] [CrossRef] [PubMed]
  56. Gilar, M.; Olivova, P.; Daly, A.E.; Gebler, J.C. Orthogonality of Separation in Two-Dimensional Liquid Chromatography. Anal. Chem. 2005, 77, 6426–6434. [Google Scholar] [CrossRef] [PubMed]
  57. Shen, Z.; Want, E.J.; Chen, W.; Keating, W.; Nussbaumer, W.; Moore, R.; Gentle, T.M.; Siuzdak, G. Sepsis Plasma Protein Profiling with Immunodepletion, Three-Dimensional Liquid Chromatography Tandem Mass Spectrometry, and Spectrum Counting. J. Proteome Res. 2006, 5, 3154–3160. [Google Scholar] [CrossRef]
  58. Betancourt, L.H.; De Bock, P.-J.; Staes, A.; Timmerman, E.; Perez-Riverol, Y.; Sanchez, A.; Besada, V.; Gonzalez, L.J.; Vandekerckhove, J.; Gevaert, K. SCX charge state selective separation of tryptic peptides combined with 2D-RP-HPLC allows for detailed proteome mapping. J. Proteom. 2013, 91, 164–171. [Google Scholar] [CrossRef]
  59. Zhao, P.; Schulz, T.C.; Sherrer, E.S.; Weatherly, D.B.; Robins, A.J.; Wells, L. The human embryonic stem cell proteome revealed by multidimensional fractionation followed by tandem mass spectrometry. Proteomics 2015, 15, 554–566. [Google Scholar] [CrossRef] [Green Version]
  60. Zhao, M.; Li, M.; Yang, Y.; Guo, Z.; Sun, Y.; Shao, C.; Li, M.; Sun, W.; Gao, Y. A comprehensive analysis and annotation of human normal urinary proteome. Sci. Rep. 2017, 7, 3024. [Google Scholar] [CrossRef]
  61. Spicer, V.; Ezzati, P.; Neustaeter, H.; Beavis, R.C.; Wilkins, J.A.; Krokhin, O.V. 3D HPLC-MS with Reversed-Phase Separation Functionality in All Three Dimensions for Large-Scale Bottom-Up Proteomics and Peptide Retention Data Collection. Anal. Chem. 2016, 88, 2847–2855. [Google Scholar] [CrossRef] [PubMed]
  62. Boichenko, A.P.; Govorukhina, N.; van der Zee, A.G.J.; Bischoff, R. Multidimensional separation of tryptic peptides from human serum proteins using reversed-phase, strong cation exchange, weak anion exchange, and fused-core fluorinated stationary phases. J. Sep. Sci. 2013, 36, 3463–3470. [Google Scholar] [CrossRef] [PubMed]
  63. Loroch, S.; Schommartz, T.; Brune, W.; Zahedi, R.P.; Sickmann, A. Multidimensional electrostatic repulsion–hydrophilic interaction chromatography (ERLIC) for quantitative analysis of the proteome and phosphoproteome in clinical and biomedical research. Biochim. Biophys. Acta (BBA)-Proteins Proteom. 2015, 1854, 460–468. [Google Scholar] [CrossRef] [PubMed]
  64. Bandhakavi, S.; Stone, M.D.; Onsongo, G.; Van Riper, S.K.; Griffin, T.J. A Dynamic Range Compression and Three-Dimensional Peptide Fractionation Analysis Platform Expands Proteome Coverage and the Diagnostic Potential of Whole Saliva. J. Proteome Res. 2009, 8, 5590–5600. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  65. Millioni, R.; Tolin, S.; Fadini, G.P.; Falda, M.; van Breukelen, B.; Tessari, P.; Arrigoni, G. High confidence and sensitivity four-dimensional fractionation for human plasma proteome analysis. Amino Acids 2012, 43, 2199–2202. [Google Scholar] [CrossRef]
  66. Alpert, A.J. Hydrophilic-interaction chromatography for the separation of peptides, nucleic acids and other polar compounds. J. Chromatogr. A 1990, 499, 177–196. [Google Scholar] [CrossRef]
  67. Zhou, H.; Di Palma, S.; Preisinger, C.; Peng, M.; Polat, A.N.; Heck, A.J.R.; Mohammed, S. Toward a Comprehensive Characterization of a Human Cancer Cell Phosphoproteome. J. Proteome Res. 2013, 12, 260–271. [Google Scholar] [CrossRef]
  68. Pernikářová, V.; Sedláček, V.; Potěšil, D.; Procházková, I.; Zdráhal, Z.; Bouchal, P.; Kučera, I. Proteomic responses to a methyl viologen-induced oxidative stress in the wild type and FerB mutant strains of Paracoccus denitrificans. J. Proteom. 2015, 125, 68–75. [Google Scholar] [CrossRef]
  69. Chen, W.; Adhikari, S.; Chen, L.; Lin, L.; Li, H.; Luo, S.; Yang, P.; Tian, R. 3D-SISPROT: A simple and integrated spintip-based protein digestion and three-dimensional peptide fractionation technology for deep proteome profiling. J. Chromatogr. A 2017, 1498, 207–214. [Google Scholar] [CrossRef]
  70. Xue, L.; Lin, L.; Zhou, W.; Chen, W.; Tang, J.; Sun, X.; Huang, P.; Tian, R. Mixed-mode ion exchange-based integrated proteomics technology for fast and deep plasma proteome profiling. J. Chromatogr. A 2018, 1564, 76–84. [Google Scholar] [CrossRef]
  71. Ishihama, Y.; Rappsilber, J.; Mann, M. Modular Stop and Go Extraction Tips with Stacked Disks for Parallel and Multidimensional Peptide Fractionation in Proteomics. J. Proteome Res. 2006, 5, 988–994. [Google Scholar] [CrossRef] [PubMed]
  72. Rappsilber, J.; Mann, M.; Ishihama, Y. Protocol for micro-purification, enrichment, pre-fractionation and storage of peptides for proteomics using StageTips. Nat. Protoc. 2007, 2, 1896–1906. [Google Scholar] [CrossRef] [PubMed]
  73. Kulak, N.A.; Pichler, G.; Paron, I.; Nagaraj, N.; Mann, M. Minimal, encapsulated proteomic-sample processing applied to copy-number estimation in eukaryotic cells. Nat. Methods 2014, 11, 319–324. [Google Scholar] [CrossRef] [PubMed]
  74. Adachi, J.; Hashiguchi, K.; Nagano, M.; Sato, M.; Sato, A.; Fukamizu, K.; Ishihama, Y.; Tomonaga, T. Improved Proteome and Phosphoproteome Analysis on a Cation Exchanger by a Combined Acid and Salt Gradient. Anal. Chem. 2016, 88, 7899–7903. [Google Scholar] [CrossRef] [PubMed]
  75. McDonald, W.H.; Ohi, R.; Miyamoto, D.T.; Mitchison, T.J.; Yates, J.R. Comparison of three directly coupled HPLC MS/MS strategies for identification of proteins from complex mixtures: Single-dimension LC-MS/MS, 2-phase MudPIT, and 3-phase MudPIT. Int. J. Mass Spectrom. 2002, 219, 245–251. [Google Scholar] [CrossRef]
  76. Wei, J.; Sun, J.; Yu, W.; Jones, A.; Oeller, P.; Keller, M.; Woodnutt, G.; Short, J.M. Global Proteome Discovery Using an Online Three-Dimensional LC−MS/MS. J. Proteome Res. 2005, 4, 801–808. [Google Scholar] [CrossRef] [PubMed]
  77. Wang, F.; Chen, R.; Zhu, J.; Sun, D.; Song, C.; Wu, Y.; Ye, M.; Wang, L.; Zou, H. A Fully Automated System with Online Sample Loading, Isotope Dimethyl Labeling and Multidimensional Separation for High-Throughput Quantitative Proteome Analysis. Anal. Chem. 2010, 82, 3007–3015. [Google Scholar] [CrossRef]
  78. Song, C.; Wang, F.; Ye, M.; Cheng, K.; Chen, R.; Zhu, J.; Tan, Y.; Wang, H.; Figeys, D.; Zou, H. Improvement of the Quantification Accuracy and Throughput for Phosphoproteome Analysis by a Pseudo Triplex Stable Isotope Dimethyl Labeling Approach. Anal. Chem. 2011, 83, 7755–7762. [Google Scholar] [CrossRef]
  79. Xu, B.; Wang, F.; Song, C.; Sun, Z.; Cheng, K.; Tan, Y.; Wang, H.; Zou, H. Large-Scale Proteome Quantification of Hepatocellular Carcinoma Tissues by a Three-Dimensional Liquid Chromatography Strategy Integrated with Sample Preparation. J. Proteome Res. 2014, 13, 3645–3654. [Google Scholar] [CrossRef]
  80. Zhou, F.; Sikorski, T.W.; Ficarro, S.B.; Webber, J.T.; Marto, J.A. Online Nanoflow Reversed Phase-Strong Anion Exchange-Reversed Phase Liquid Chromatography–Tandem Mass Spectrometry Platform for Efficient and In-Depth Proteome Sequence Analysis of Complex Organisms. Anal. Chem. 2011, 83, 6996–7005. [Google Scholar] [CrossRef] [Green Version]
  81. Ficarro, S.B.; Zhang, Y.; Carrasco-Alfonso, M.J.; Garg, B.; Adelmant, G.; Webber, J.T.; Luckey, C.J.; Marto, J.A. Online Nanoflow Multidimensional Fractionation for High Efficiency Phosphopeptide Analysis. Mol. Cell. Proteom. 2011, 10. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  82. Zhou, F.; Lu, Y.; Ficarro, S.B.; Adelmant, G.; Jiang, W.; Luckey, C.J.; Marto, J.A. Genome-scale proteome quantification by DEEP SEQ mass spectrometry. Nat. Commun. 2013, 4, 2171. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  83. Law, H.C.H.; Kong, R.P.W.; Szeto, S.S.W.; Zhao, Y.; Zhang, Z.; Wang, Y.; Li, G.; Quan, Q.; Lee, S.M.Y.; Lam, H.C.; et al. A versatile reversed phase-strong cation exchange-reversed phase (RP–SCX–RP) multidimensional liquid chromatography platform for qualitative and quantitative shotgun proteomics. Analyst 2015, 140, 1237–1252. [Google Scholar] [CrossRef] [PubMed]
  84. Fournier, M.L.; Gilmore, J.M.; Martin-Brown, S.A.; Washburn, M.P. Multidimensional Separations-Based Shotgun Proteomics. Chem. Rev. 2007, 107, 3654–3686. [Google Scholar] [CrossRef]
  85. Motoyama, A.; Yates, J.R. Multidimensional LC Separations in Shotgun Proteomics. Anal. Chem. 2008, 80, 7187–7193. [Google Scholar] [CrossRef] [Green Version]
  86. Guiochon, G.; Marchetti, N.; Mriziq, K.; Shalliker, R.A. Implementations of two-dimensional liquid chromatography. J. Chromatogr. A 2008, 1189, 109–168. [Google Scholar] [CrossRef]
  87. Bekker-Jensen, D.B.; Kelstrup, C.D.; Batth, T.S.; Larsen, S.C.; Haldrup, C.; Bramsen, J.B.; Sørensen, K.D.; Høyer, S.; Ørntoft, T.F.; Andersen, C.L.; et al. An Optimized Shotgun Strategy for the Rapid Generation of Comprehensive Human Proteomes. Cell Syst. 2017, 4, 587–599. [Google Scholar] [CrossRef] [Green Version]
  88. Meier, F.; Brunner, A.-D.; Koch, S.; Koch, H.; Lubeck, M.; Krause, M.; Goedecke, N.; Decker, J.; Kosinski, T.; Park, M.A.; et al. Online Parallel Accumulation–Serial Fragmentation (PASEF) with a Novel Trapped Ion Mobility Mass Spectrometer. Mol. Cell. Proteom. 2018, 17, 2534–2545. [Google Scholar] [CrossRef] [Green Version]
  89. Anjo, S.I.; Santa, C.; Manadas, B. SWATH-MS as a tool for biomarker discovery: From basic research to clinical applications. Proteomics 2017, 17, 1600278. [Google Scholar] [CrossRef]
  90. Kawashima, Y.; Watanabe, E.; Umeyama, T.; Nakajima, D.; Hattori, M.; Honda, K.; Ohara, O. Optimization of Data-Independent Acquisition Mass Spectrometry for Deep and Highly Sensitive Proteomic Analysis. Int. J. Mol. Sci. 2019, 20, 5932. [Google Scholar] [CrossRef] [Green Version]
  91. Keshishian, H.; Burgess, M.W.; Specht, H.; Wallace, L.; Clauser, K.R.; Gillette, M.A.; Carr, S.A. Quantitative, multiplexed workflow for deep analysis of human blood plasma and biomarker discovery by mass spectrometry. Nat. Protoc. 2017, 12, 1683–1701. [Google Scholar] [CrossRef] [PubMed]
  92. Mun, D.-G.; Bhin, J.; Kim, S.; Kim, H.; Jung, J.H.; Jung, Y.; Jang, Y.E.; Park, J.M.; Kim, H.; Jung, Y.; et al. Proteogenomic Characterization of Human Early-Onset Gastric Cancer. Cancer Cell 2019, 35, 111–124. [Google Scholar] [CrossRef] [PubMed] [Green Version]
Figure 1. Integrated devices enabling both sample preparation and fractionation. (A) Example of a triple StageTip, consisting of C18−SCX−C18-material; reprinted with permission from [71], Copyright (2006) American Chemical Society. (B) Three-dimensional (3D)-SISPROT that allows strong anion exchange chromatography (SAX) fractionation followed by high-pH reverse phase liquid chromatography (RPLC) fractionation prior to low-pH RPLC-MS/MS analysis; reprinted and modified from [69], Copyright (2017) with permission from Elsevier.
Figure 1. Integrated devices enabling both sample preparation and fractionation. (A) Example of a triple StageTip, consisting of C18−SCX−C18-material; reprinted with permission from [71], Copyright (2006) American Chemical Society. (B) Three-dimensional (3D)-SISPROT that allows strong anion exchange chromatography (SAX) fractionation followed by high-pH reverse phase liquid chromatography (RPLC) fractionation prior to low-pH RPLC-MS/MS analysis; reprinted and modified from [69], Copyright (2017) with permission from Elsevier.
Ijms 21 01524 g001
Figure 2. Arrangement in two online 3D-LC platforms. (A) Schematic diagram of automated, online nanoflow RP-SAX-RP platform. Reprinted with permission from [80], Copyright (2011) American Chemical Society. (B) The detailed layout of the capillary-/nano-flow setup using two switching valves. Reprinted with permission from [83], Copyright (2015) Royal Society of Chemistry.
Figure 2. Arrangement in two online 3D-LC platforms. (A) Schematic diagram of automated, online nanoflow RP-SAX-RP platform. Reprinted with permission from [80], Copyright (2011) American Chemical Society. (B) The detailed layout of the capillary-/nano-flow setup using two switching valves. Reprinted with permission from [83], Copyright (2015) Royal Society of Chemistry.
Ijms 21 01524 g002
Figure 3. Experimental design of two combined online and offline 3D-LC platforms for proteomic applications. (A) Large-scale proteome quantification of human hepatocellular carcinoma and normal liver tissues using high-pH RPLC pre-fractionation and online SCX−RP 2D nanoflow LC−MS/MS analysis. Reprinted with permission from [79], Copyright (2014) American Chemical Society. (B) Mouse brain proteome investigation using online SCX-RPLC fractionation and capillary zone electrophoresis (CZE)-MS/MS analysis. Reprinted and modified from [51], Copyright (2018) with permission from Elsevier.
Figure 3. Experimental design of two combined online and offline 3D-LC platforms for proteomic applications. (A) Large-scale proteome quantification of human hepatocellular carcinoma and normal liver tissues using high-pH RPLC pre-fractionation and online SCX−RP 2D nanoflow LC−MS/MS analysis. Reprinted with permission from [79], Copyright (2014) American Chemical Society. (B) Mouse brain proteome investigation using online SCX-RPLC fractionation and capillary zone electrophoresis (CZE)-MS/MS analysis. Reprinted and modified from [51], Copyright (2018) with permission from Elsevier.
Ijms 21 01524 g003
Table 1. Performance of various offline 3D-LC systems.
Table 1. Performance of various offline 3D-LC systems.
3D-LC setupSample (Protein Amount)MSIdentified Proteins *Identified Unique PeptidesFraction NumberMS Time (h)Year, Reference
RP-SCX-RPHuman plasma (500 µg)Agilent 1100 LC/MSD Trap484-401002006, [57]
SEC-SCX-RPHuman liver (1 mg)QSTARXL63634511202062007, [55]
SEC-HILIC-RPHuman serum (7.4 mg)Quadrupole ion trap1955-20602011, [31]
ERLIC- RP- RPHuman serum (1.2 mg)QTOF10882081442162013, [62]
SCX-RP-RPMouse embryonic fibroblast (1 mg)LTQ Orbitrap XL505129,84330-2013, [58]
SCX-HILIC-RPK562 cells (3 mg)LTQ-Orbitrap Velos470822,148631262013, [67]
SCX-HILIC-RPHeLa cells (500 µg)LTQ-Orbitrap Velos342411,980631262013, [67]
SEC-HILIC-RPParacoccus denitrificans (8 mg)Orbitrap Elite2627-36662015, [68]
SCX-RP-RPHuman embryonic stem cell (-)Thermo Finnigan LTQ3184~24,0001001172015, [59]
RP- RP- RPJurkat cells (720 µg)TripleTOF 560014,230251,1661261892016, [61]
GELFrEE-RP-RP & LPIEF-RP-RPHuman urine (5 mg)TripleTOF 5600608568,1513607202017, [60]
SAX-RP-RPHEK 293T cells (30 µg)Orbitrap Fusion822274,4321120.42017, [69]
SCX & SAX-RP-RPHuman serum (-)Orbitrap Fusion862-12122018, [70]
* Proteins identified with at least two peptides. A minus sign indicates no reported information.
Table 2. Performance of some online 3D-LC systems.
Table 2. Performance of some online 3D-LC systems.
3D-LC SetupSample (Amount)MSIdentified Proteins *Identified Unique PeptidesFraction NumberMS Time (h)Year, Reference
RP-SCX-RPSaccharomyces cerevisiae (200 µg)LCQ Deca XP~1900-601402005, [76]
RP-SAX-RPSaccharomyces cerevisiae (5 µg)Orbitrap XL400426,4681012022011, [80]
382125,091511022011, [80]
RP-SAX-RPMurine embryonic stem cells (25 µg)Orbitrap XL11,352211,535205802013, [82]
RP-SCX-RPPC12 cell (100 µg)AB Sciex QSTAR XL QTOF634597,30912242015, [83]
* Proteins identified with at least two peptides.
Table 3. Performance of 2 combined offline-online 3D-LC systems.
Table 3. Performance of 2 combined offline-online 3D-LC systems.
Pre-FractionationLC SetupSample (Amount)MSIdentified Proteins *Identified Unique PeptidesFraction NumberMS Time (h)Year, Reference
RPSCX-RPHuman liver (200 µg)LTQ-Orbitrap Velos2759-361242014, [79]
SCX-RPCZEMouse brain (500 µg)Q-Exactive HF820065,00060702018, [51]
* Proteins identified with at least two peptides.
Table 4. Comparison of online and offline 3D-LC strategies.
Table 4. Comparison of online and offline 3D-LC strategies.
FeatureOffline 3D-LCOnline 3D-LC
SetupSimpleUsually sophisticated
Ability to transfer technologies to other laboratoriesHighLow-medium
Sample amountHigh, up to several mg
Not suitable for samples with a limited amount
Low, from several µg to 100 µg
Allow only low-amount samples
OperationSeparated dimensions, simple and flexible to operateUsually full-automation, well-trained skill required
Sample poolingAllowUsually not allow
Sample handlingHighLow
Sample lossHigh-mediumLow
Table 5. Performance comparison among various 1D, 2D, and 3D-LC systems.
Table 5. Performance comparison among various 1D, 2D, and 3D-LC systems.
SampleMSParamater1D2D3DReference
HEK 293T cellsOrbitrap FusionSample amount (µg)63030[69]
SetupRPSAX-RPSAX-RP-RP
Id. proteins4275 ± 265380 ± 888222 ± 109
Id. unique peptides19,768 ± 33334,912 ± 92574,432 ± 996
Fraction number1311
MS time (h)1.44.220.4
Jurkat cellsTripleTOF 5600Sample amount (µg)1200720[61]
SetupRPRP-RPRP-RP-RP
Id. proteins2568875714,230
Id. unique peptides11,878109,461251,166
Fraction number121126
MS time (h)1.531.5189
HeLa cells & K562 cellsLTQ-Orbitrap VelosSample amount (µg) *125 and 750500 and 3000500[67]
SetupRPHILIC-RPSCX-HILIC-RP
Unique phos.pro. *1570 and 17633891 and 41323424 and 4708
Unique phos.pep. *3726 and 410416,637 and 16,72211,980 and 22,148
Fraction number12063
MS time (h)240126
Mouse embryonic fibroblastAB Sciex QSTAR XL QTOFSample amount (µg) 1515[83]
Setup RP-RPRP-SCX-RP
Id. proteins 23583114
Id. unique peptides 13,57325,792
Human urineTripleTOF 5600Sample amount (µg)202005000[60]
SetupRPRP-RPGELFrEE-RP-RP and LPIEF-RP-RP
Id. proteins80831626085
Id. unique peptides13,89525,94068,151
Fraction number120360
MS time (h)2 × 340720
Mouse brainQ-Exactive HFSample amount (µg) 500500[51]
Setup RP-RPSCX-RP-CZE
Id. proteins 89008200
Id. unique peptides 70,00065,000
Fraction number 3060
MS time (h) 6070
E. coliLCQ Deca XP ion trapSample amount (µg) 2020[80]
Setup RP-RPRP-SAX-RP
Id. proteins 702923
Id. unique peptides 29234254
Fraction number 4037
MS time (h) 8074
Identified proteins are those with at least two peptides. * Two numbers in each position are for HeLa cells and K562 cells, respectively. Id.: Identified; phos.pro.: phosphoproteins; phos.pep.: phosphopeptides.

Share and Cite

MDPI and ACS Style

Duong, V.-A.; Park, J.-M.; Lee, H. Review of Three-Dimensional Liquid Chromatography Platforms for Bottom-Up Proteomics. Int. J. Mol. Sci. 2020, 21, 1524. https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21041524

AMA Style

Duong V-A, Park J-M, Lee H. Review of Three-Dimensional Liquid Chromatography Platforms for Bottom-Up Proteomics. International Journal of Molecular Sciences. 2020; 21(4):1524. https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21041524

Chicago/Turabian Style

Duong, Van-An, Jong-Moon Park, and Hookeun Lee. 2020. "Review of Three-Dimensional Liquid Chromatography Platforms for Bottom-Up Proteomics" International Journal of Molecular Sciences 21, no. 4: 1524. https://0-doi-org.brum.beds.ac.uk/10.3390/ijms21041524

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop