"Inhibitory effects of human á2-Macroglobulin on Trypanosoma cruzi epimastigote proteinases".

RAMOS A; REMEDI MS; SANCHEZ MC; BONACCI G; VIDES MA; CHIABRANDO GA

ACTA TROPICA

ELSEVIER SCIENCE BV

Año: 1997 vol. 68 p. 327 - 327

0001-706X

he inactivation of Trypanosoma cruzi proteinases by human a2-macroglobulin (a2-M), amajor plasma proteinase inhibitor was studied. Evidences regarding the interaction betweena2-M and proteolytic enzymes contained in crude cell-free extracts of T. cruzi were derivedfrom electrophoretic and enzymatic assays. The former showed conformational and structural changes ocurring in a2-M, as judged by the appearance of transformed ‘fast’ form onnative PAGE; generation of bands of :90 kDa on reduced SDS-PAGE and formation ofcovalent complexes enzyme-inhibitor on SDS-PAGE. On the other hand, the total proteolytic activity on azocasein dropped significantly in the presence of a2-M, although partialactivity was still maintained. The proteinases detected as a double band of 44 and 53 kDa ongelatin SDS-PAGE were also inhibited by a2-M. Results suggest that the study of specificinteractions between a2-M and T. cruzi-proteinases, probably with cruzipain, could bebiologically important in the fate of T.