TRYPANOSOMA-CRUZI - IDENTIFICATION OF PROTEINASES IN SHED COMPONENTS OF TRYPOMASTIGOTE FORMS

Trypanosoma cruzi trypomastigotes were shown to predominantly release high molecular weight components (above 50 kDa) when allowed to shed f or I hour in protein-free media. Under these conditions, parasites wer e not damaged or lysed, as was indicated by: (a) their normal mobility ; (b) their retaining of some of the labelled proteins; (c) the unchan ged pattern of biotinylated surface proteins after shedding. Shed comp onents were shown to display proteinase activities, detected at 97 and 50/60 kDa in gelatin gels. These proteolytic activities were complete ly inhibited by E-64, indicating that they were due to cysteine protei nases.