In vitro synthesis of Trypanosoma cruzi antigenic polypeptides.

A ribosomal fraction of Trypanosoma cruzi was isolated with detergent lysis and differential ultracentrifugation. This ribosomal fraction directed in vitro protein synthesis, in a heterologous incorporation system (rat liver pH 5 fraction), leading to values up to 10 times higher than endogenous control. The ideal concentrations of Mg2+, K+, and ribosomal proteins and the time of incubation of the incorporation mixtures were 6 mM, 21 mM, 60 microliters, and 45 min, respectively. The product thus obtained was analyzed by fluorography after polyacrylamide-sodium dodecyl sulfate gel electrophoresis and showed the presence of many protein bands, but few bands were present in the immunoprecipitate obtained with serum from Chagas' disease patients. This product was able to react with anti-T. cruzi antibodies when submitted to an immunoenzymatic assay.