Partial characterization of serine proteinases secreted by adult Trichinella spiralis.

Serine proteinases secreted by adult Trichinella spiralis were isolated from excretory/secretory products (ES) of in-vitro-cultured parasites by affinity chromatography with p-benzamidine-celite. The purified enzymes had molecular weights of approximately 18, 40, and 50 kDa and displayed enzyme activity against a range of low-molecular-weight substrates, gelatin, and azocasein. The antigenicity of these parasite proteinases was demonstrated by the inhibition of enzymatic activity with IgG purified from infected hosts. The inactivation of major secreted proteinases of adult T. spiralis by immune antibody could presumably contribute to impairment of the survival of the parasite in sensitized hosts.