Immunochemical Studies of the Major Internal Polypeptide of Woolly Monkey and Gibbon APE Type C Viruses

The major internal protein of the type C virus isolated from a Woolly monkey by Theilen and colleagues was purified by isoelectric focusing and used to raise specific antibody in guinea pigs. The protein has an isoelectric point of 6.5 to 6.6, and a molecular weight of 29,500 based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Gel diffusion analyses showed a high degree of relationship to the type C virus isolated from a Gibbon ape by Kawakami and colleagues, while sera indicating this relationship were nonreactive with other mammalian type C viruses, except in highly sensitive radioimmunosassays. The “primate” viral proteins clearly contain determinants cross-reactive with the homologous protein in other mammalian type C viruses; however, heterogeneity of these cross-reactive determinants was indicated by differential reactivity of certain cross-reactive sera.