Dear Colleagues,

The folding of proteins is recognized as one of the most complex processes in Biochemistry since its understanding also implies the characterization, from the unfolded state, of all conformational changes such as intermediate and transition states that separate the unfolded polypeptide from its fully folded and active form. The situation is also rendered more complicated because most of the proteins are made of several domains all having their own thermodynamic and kinetics parameters of folding. Counter pressures are also exerted by the possible existence of disulfide bridges which have to be appropriately paired through oxidative processes driven by the Dsb disulfide bonds generation machinery implicating oxido-reductases and isomerases as well as by the existence of the cis- and trans- possible configuration of the peptide bonds immediately preceding the prolyl residues. This cis-trans isomerization is dependent on an ubiquitous class of foldases known as peptidyl-prolyl cis-trans isomerases. The folding of nascent polypeptides is also assisted by special proteins, known as chaperones that also play crucial roles in protecting proteins against irreversible misfolding possibly induced by various cellular stresses such as heat shock or cold shock for example. Although the existence of intermediates are not always required for efficient folding they are obviously generally essential in helping to restrict the conformational zones and to direct the molecule towards its final low energy state. They have been identified and monitored by stopped-flow techniques making use of chemical denaturants or physical methods such as pressure perturbation recently found to be quite able to precise the folding landscape of a protein that provides the basis of the understanding of protein folding.

The aim of this special issue is to illustrate, through selected examples, the progresses which has been recently made, both on theoretical and technical grounds, in the understanding of the folding process of proteins nowadays of crucial importance due to the discovery of the relationship existing between protein misfolding and various human diseases derived from neurodegenerative disorders such as Alzheimer’s and Parkinson’s disease.

Prof. Dr. Charles Gerday
Guest Editor

• protein folding
• chaperones
• foldases
• stopped-flow
• energy landscape

• Protein Folding 2009 in International Journal of Molecular Sciences (25 articles)
• Protein Folding in International Journal of Molecular Sciences (65 articles)