title: Immunochemistry of the Moloney MuLV gp71 molecule-1. Distribution of antigenic determinants on the products of digestion by Staphylococcus aureus protease.
abstract: The antigenic characterization of Moloney murine leukemia virus gp71 was carried out by cleavage with Staphylococcus aureus protease. The whole molecule and two fragments of 43,000 and 32,000 daltons were immunoprecipitated with monospecific anti-type, group and interspecies antiserum. The three native molecules were recognized by anti-type antibodies, but only the gp71 and the 32,000-dalton molecule seemed to retain group-specific antigenic determinants. No interspecies determinants were detected on the two products of digestion. A similar pattern of precipitation was found with SDS-denatured antigens. The results suggest that sequential structures contribute to the type-specific antigenic determinants, because they were not destroyed by SDS unfolding or by the change in the protein conformation that follows enzymatic cleavage. Interspecies determinants seem to be mainly conformational, since they disappeared from the whole molecule and the two peptides after the same treatment. Group-specific determinants appear to be intermediate: they disappeared after the conformational change on the native 43K but not on the 32K peptide and the monospecific anti-group antibody showed an intermediate ability to precipitate the SDS-unfolded antigens.
mesh_terms: D000914:Antibodies, Viral; D000918:Antibody Specificity; D000956:Antigens, Viral / Q000276:immunology*; D010450:Endopeptidases / Q000378:metabolism; D000939:Epitopes; D006023:Glycoproteins / Q000276:immunology; D008979:Moloney murine leukemia virus / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology; D011489:Protein Denaturation; D012697:Serine Endopeptidases; D013211:Staphylococcus aureus / Q000201:enzymology; D014759:Viral Envelope Proteins; D014764:Viral Proteins / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D000939:Epitopes; D006023:Glycoproteins; D010446:Peptide Fragments; D014759:Viral Envelope Proteins; D014764:Viral Proteins; D010450:Endopeptidases; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase