title: Exoantigens from trypanosoma cruzi contain cruzipain.
abstract: This paper shows that human antibodies specific for exoantigens of pI 4.5 (Eas 4.5), released by the blood forms of the parasite, obtained from chagasic patients sera by immunoabsorption react with cruzipain, the major cysteinyl proteinase of Trypanosoma cruzi. Sera from mice immunized with Eas 4.5 also recognize cruzipain. In addition, mouse antisera to cruzipain were reactive with Eas 4.5 as well as with total antigens excreted by culture-trypomastigotes. This reactivity was inhibited by cruzipain as revealed by enzyme-linked immunosorbent assay (ELISA). Furthermore, it was observed by immunoblot that the exoantigens recognized by mouse antisera to cruzipain have molecular weights between 50 and 60 kDa and human antibodies specific for Eas 4.5 recognize cruzipain with apparent molecular weight of 50 kDa. These findings suggest the presence of cruzipain in Eas and the subsequent release of this enzyme by the parasite.
authors.affiliation: Departamento de Bioquímica Clinica, Facultad de Ciencias Químicas, Universidad Nacional de Cordoba, Argentina. agruppi@fisquim.uncor.edu
authors.forename: A
authors.initials: A
authors.lastname: Gruppi
authors.forename: F M
authors.initials: FM
authors.lastname: Cerbán
authors.forename: E
authors.initials: E
authors.lastname: Vottero-Cima
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000032:analysis*; D015153:Blotting, Western; D014355:Chagas Disease / Q000097:blood / Q000276:immunology*; D003546:Cysteine Endopeptidases / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007163:Immunosorbent Techniques; D051379:Mice; D015800:Protozoan Proteins; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D015800:Protozoan Proteins; D003546:Cysteine Endopeptidases; C063214:cruzipain