Folia Parasitologica 47[2] 141-145 (2000) | DOI: 10.14411/fp.2000.027

Proteolytic enzymes secreted by larval stage of the parasitic nematode Trichinella spiralis

Valentina K. Todorova

Institute of Molecular Biology, Bulgarian Academy of Sciences, Acad. G. Bonchev St., Bldg. 21, 1113 Sofia, Bulgaria

Excretory/secretory products (ES), collected from in vitro cultures of muscle larvae (L1) of Trichinella spiralis (Owen, 1835) were examined for the presence of proteolytic enzymes. Several discrete proteinases in the size range of 25-55 kDa were identified by substrate gel electrophoresis and were characterised according to pH optima, substrate specificity and inhibitor sensitivity using azocasein assay. Serine, cysteine and metalloproteinases active at pH 5-7 were identified. The serine proteinases were found to predominate and some of them were found to be specific for the larval stage of the parasite. The results from the substrate analysis indicated the presence of collagenolytic and elastolytic activities. The proteinase activity was inhibited by IgG isolated from T. spiralis-infected mice, an observation of relevance to understanding host/parasite interactions and, ultimately, the development of anti-Trichinella vaccine.

Keywords: antibody inhibition, excreted/secreted products, larval stage, serine proteinases, Trichinella spiralis

Received: August 3, 1999; Accepted: October 25, 1999; Published: June 1, 2000  Show citation