An antigenically related tryptic polypeptide from several mammalian type C RNA virus p30s

Limited tryptic digestion of p30 antigen (the major internal viral protein) of type C viruses isolated from hamster, rat, and gibbon ape yielded a polypeptide fragment with a molecular weight of approximately 10,000 daltons. Some antigenic determinants with interspecies specificity were retained on these polypeptides, which in serological tests cross-reacted with antibody produced previously against a similar fragment obtained from mouse p30. Exhaustive trypsinization resulted in further fragmentation with concomitant loss of serologic activity. The results suggest that all mammalian type C virus p30s have an antigenically related polypeptide core which is not readily digested by trypsin.