Characterisation of seryl tRNA synthetase (srs-2) in Haemonchus contortus and Teladorsagia circumcincta
Year: 2024
Type: article
Abstract: The aim of the study was to purify and characterise recombinant proteins with the potential as an anti-parasite vaccine. Full-length cDNAs encoding seryl-tRNA synthetase ( srs-2 ) were cloned from Haemonchus contortus ( Hc SRS-2) and Teladorsagia circumcincta ( Tc SRS-2). Tc SRS-2 and Hc SRS-2 cDNA (1458bp) encoded proteins of 486 amino acids , each of which was present as a single band of about 55 kDa on SDS-PAGE. Multiple alignments of the protein sequences showed homology of 94% between Tc SRS-2 and Hc SRS-2, 76–93% with SRS-2s of eight nematodes and 68% with Mus musculus SRS-2. The predicted three-dimensional structures revealed an overall structural homology of Tc SRS-2 and Hc SRS-2, highly conserved binding and catalytic sites, and minor differences in the tautomerase binding site residues in other nematode SRS-2 homologues. A phylogenetic tree was constructed using helminth and mammalian SRS-2 sequences. Soluble C-terminal SRS-2 proteins were expressed in Escherichia coli strain AY2.4 and purified. Recombinant Hc SRS-2 assay shows that the recombinant enzyme was active and stable. The K m and V max for ATP were 3.9 ± 1.0 μM and 2.7 ± 0.1 μmol min −1 mg −1 protein, respectively. Antibodies in serum and saliva from field-immune, but not nematode-naïve, sheep recognised recombinant Hc SRS-2 and Tc SRS-2 in enzyme-linked immunosorbent assays. Recognition of the recombinant proteins by antibodies generated by exposure of sheep to the native enzyme indicates similar antigenicity of the two proteins.
Source: Experimental Parasitology
Institutions: AgResearch, La Trobe University
Language: English
Subfield: Small Animals
Field: Veterinary
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,340
Award: G6508886867
OpenAlex ID: W4402879603