title: Envelope glycoproteins of Rauscher murine leukemia virus: isolation and chemical characterization.
abstract: The envelope glycoproteins (designated gp70 and gp45) of the Rauscher strain of murine leukemia virus were solubilized by osmotic shock and freeze-thawing in chaotropic solutions. The viral glycoproteins were then purified by phosphocellulose chromatography and gel permeation chromatography on Bio-Gel A-1.5m. Yields by this procedure were 6.2% for gp70 and 1.3% for gp45 on a protein input basis. The apparent molecular weights were respectively 67 500 and 47 500 with a polypeptide chain molecular weight of approximately 45 000 for both glycoproteins. Amino acid analysis showed a high degree of similarity for both components, with some differences subject to further evaluation. The total carbohydrate content was approximately 32% for gp70 and 6-9% for gp45. In keeping with the amino acid compositional similarity suggesting relationships, alanine was found to ba the amino-terminal amino acid of both glycoproteins, and cross-reactivity was demonstrated by immunologic tests. The data suggest that the chief difference between gp70 and gp45 lies in the carbohydrate content.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D006023:Glycoproteins / Q000276:immunology / Q000302:isolation & purification; D006041:Goats / Q000276:immunology; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D008970:Molecular Weight; D011925:Rauscher Virus / Q000032:analysis* / Q000648:ultrastructure; D012794:Sialic Acids / Q000032:analysis; D014764:Viral Proteins / Q000276:immunology / Q000302:isolation & purification
chemical_list: D000596:Amino Acids; D006023:Glycoproteins; D012794:Sialic Acids; D014764:Viral Proteins