In vitro expression of a recombinant paramyosin of Ancylostoma caninum

The objective of this study was to characterise a recombinant antigen of Ancylostoma caninum that had been identified by immunoscreening with selected antisera described elsewhere. In vitro expression of clone 341 produced a protein with an apparent molecular mass of approximately 34 kDa which was recognised in Western blots by antisera against whole worms and antisera against esophagi from adult worms, but not by sera from experimentally infected dogs or rabbits. DNA sequencing showed a cDNA of 1176 bp coding for a 34-kDa protein, similar to the size identified in the immunoblot. DNA database comparison revealed an 80-82% homology with the Caenorhabditis elegans unc-15 gene coding for paramyosin. The deduced aa sequence of clone 341 showed 95% homology with the paramyosin aa sequence of C. elegans. Affinity purified antibodies against the recombinant protein recognise a protein with an apparent molecular mass of 97 kDa of A. caninum muscle tissue fraction which is in accordance with the molecular mass of paramyosin from Schistosoma mansoni and Schistosoma japonicum.