Inhibitory Effects of Human 2-Macroglobulin on Trypanosoma cruzi Epimastigote Proteinases

RAMOS ADRIAN,; REMEDI SARA,; SÁNCHEZ CECILIA,; BONACCI GUSTAVO,; VIDES MIGUEL,; CHIABRANDO, GUSTAVO A

ACTA TROPICA

ELSEVIER

Año: 1997 vol. 68 p. 327 - 327

0001-706X

p class="abstract">The inactivation of Trypanosoma cruzi proteinases by human alpha 2-macroglobulin (alpha 2-M), a major plasma proteinase inhibitor was studied. Evidences regarding the interaction between alpha 2-M and proteolytic enzymes contained in crude cell-free extracts of T. cruzi were derived from electrophoretic and enzymatic assays. The former showed conformational and structural changes occurring in alpha 2-M, as judged by the appearance of transformed 'fast' form on native PAGE; generation of bands of approximately 90 kDa on reduced SDS-PAGE and formation of covalent complexes enzyme-inhibitor on SDS-PAGE. On the other hand, the total proteolytic activity on azocasein dropped significantly in the presence of alpha 2-M, although partial activity was still maintained. The proteinases detected as a double band of 44 and 53 kDa on gelatin SDS-PAGE were also inhibited by alpha 2-M. Results suggest that the study of specific interactions between alpha 2-M and T. cruzi-proteinas