A 1095 bp full length cDNA encoding
Teladorsagia circumcincta aldolase (
TciALDO-1) was cloned and expressed in
Escherichia coli. Recombinant
TciALDO-1 was purified, and its kinetic properties determined. The predicted protein consisted of 365 amino acids, and was present as a
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A 1095 bp full length cDNA encoding
Teladorsagia circumcincta aldolase (
TciALDO-1) was cloned and expressed in
Escherichia coli. Recombinant
TciALDO-1 was purified, and its kinetic properties determined. The predicted protein consisted of 365 amino acids, and was present as a single band of about 44 kDa on SDS-PAGE. Multiple alignments of the protein sequence of
TciALDO-1 with homologues from other helminths showed the greatest similarity (93%) to the aldolases of
Haemonchus contortus and
Dictyocaulus viviparus, 82–86% similarity to the other nematode sequences, and 68–71% similarity to cestode and trematode enzymes. Substrate binding sites and conserved regions were identified, and were completely conserved in other homologues. At 30 °C, the optimum pH for
TciALDO-1 activity was pH 7.5, the V
max was 432 ± 23 nmol × min
−1 × mg
−1 protein, and the apparent K
m for the substrate fructose 1,6-bisphosphate was 0.24 ± 0.01 µM (mean ± SEM,
n = 3). Recombinant
TciALDO-1 was recognized by antibodies in both serum and saliva from field-immune sheep in ELISA, however, that was not the case with nematode-naïve sheep.
Teladorsagia circumcincta fructose 1,6-bisphosphate aldolase appears to have potential as a vaccine candidate to control this common sheep parasite.
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