Identification and analysis of epimastigote surface and metabolic proteins in Trypanosoma cruzi

Metabolic and surface membrane proteins of four epimastigote-stage Trypanosoma cruzi clones were analyzed by one and two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. No major inter-clonal differences were observed in the metabolic protein patterns, indicating that these proteins are highly conserved. However, marked quantitative and qualitative differences were observed in surface-labeled protein patterns following both one and two-dimensional electrophoretic analyses. Inter and intra-clonal differences in antigenic properties also were demonstrated by immunoprecipitation of the surface proteins with sera from animals immunized or infected with various T. cruzi stocks. Thus, a wide spectrum of both phenotypic and antigenic diversity exists in T. cruzi which may be relevant to problems of the diagnosis and immunotherapy of Chagas' disease.