Characterization of a high molecular weight protective antigen of Plasmodium yoelii.

A 230 000 molecular weight Plasmodium yoelii protective antigen was characterized. Two monoclonal antibodies against P. yoelii immunoprecipitated the 230 000 mol. wt protein and a number of lower molecular weight polypeptides. These polypeptides were shown by peptide mapping and specific antibody binding to be fragments of the large protein. Iodination experiments suggested that the lower molecular weight species may be present on the surface of the merozoite. The protein was found not to be glycosylated. By serology, related antigens were shown to be associated with blood-stage schizonts of P. vinckei subspp., P. chabaudi subspp. and P. falciparum.