Trypanosoma cruzi: cruzipain and membrane-bound cysteine proteinase isoform(s) interact with human alpha2-macroglobulin (alpha2-M) and pregnancy zone protein (PZP).

RAMOS A; DUSCHAK V; G. DE BURGOS N; BARBOZA M; REMEDI MS; VIDES MA; CHIABRANDO GA

EXPERIMENTAL PARASITOLOGY

ELSEVIER

Año: 2002 vol. 100 p. 121 - 121

0014-4894

lasmatic levels of pregnancy zone protein (PZP) increase in children with acute Chagas disease. PZP, as well as alpha2-macroglobulin (alpha2-M), are able to interact with Trypanosoma cruzi proteinases. The interaction of alpha2-M and PZP with cruzipain, the major cysteine proteinase of T. cruzi, was investigated. Several molecular changes on both alpha-M inhibitors under reaction with cruzipain were found. PAGE analysis showed: (i) formation of complexes of intermediate mobility and tetramerization of native alpha2-M and PZP, respectively; (ii) limited proteolysis of bait region in alpha2-M and PZP, and (iii) covalent binding of cruzipain to PZP and alpha2-M. Conformational and structural changes experimented by alpha-Ms correlate with modifications of the enzyme electrophoretic mobility and activity. Cruzipain-alpha-M complexes were also detected by gelatin SDS-PAGE and immunoblotting using polyclonal anti-cruzipain antibodies. Concomitantly, alpha2-M and PZP impaired the activity of