A λgt11 cDNA recombinant that encodes Dirofilaria immitis paramyosin

Abstract

The cDNA synthesized from mRNA of Dirofilaria immitis female adult worms was cloned into the expression vector λgt11. Screening the library with a hyperimmune rabbit antiserum raised against adult worm homogenates yielded several antigen positive clones. One of these clones, λcDi2, was recognized by rabbit antisera raised against either D. immitis L-3, adult, Brugia malayi L-3 or Onchocerca volvulus adult worm antigen, as well as by antisera from humans naturally infected with O. volvulus or Wuchereria bancrofti. Affinity-purified anti-λcDi2 antibodies reacted with a 97-kDa protein on Western transfers of adult D. immitis antigen extracts that were reduced with β-mercaptoethanol. The whole rabbit anti-D. immitis adult antiserum depleted of anti-λcDi2 antibodies exhibited decreased reactivity to this 97-kDa band. A monoclonal antibody (IA6) that specifically binds Schistosoma mansoni paramyosin also recognised a 97-kDa protein in D. immitis extracts upon Western transfer. The deduced amino acid sequence of partial DNA sequence from λcDi2 showed some similarity to nematode myosin, and gave a stretch of 82 amino acids that is 91.5% identical to Caenorhabditis elegans paramyosin: thus, λcDi2 encodes D. immitis paramyosin. © 1989.