title: Murine mammary tumor virus structural protein interactions: formation of oligomeric complexes with cleavable cross-linking agents.
abstract: Murine mammary tumor virus protein interactions in the intact virion structure were studied with the use of the cleavable cross-linking reagents dithiobis(succinimidyl propionate) and methyl 4-mercaptobutyrimidate hydrochloride. Cross-linked oligomeric complexes of murine mammary tumor virus proteins were analyzed by two-dimensional gel electrophoresis. Among the complexes most consistently formed were a heterodimer of the two glycoproteins gp36 and gp52, the homodimer of gp36, and the homotrimer of gp52. A very prominent oligomer formed at higher concentrations of dithiobis(succinimidyl propionate) was a complex of about 230,000 molecular weight, made up of three molecules each of gp36 and gp52. A number of lines of evidence, including electron microscopic analysis, suggest that the 230,000-molecular-weight complex actually represents the murine mammary tumor virus spike structure. Of the murine mammary tumor virus core proteins, p14 forms homooligomers most readily. Upon cross-linking with methyl 4-mercaptobutyrimidate hydrochloride a small amount of what seems to be a heterodimer made up of the N-terminal gag protein p10 and the hydrophobic membrane glycoprotein gp36 can be observed.
mesh_terms: D003432:Cross-Linking Reagents; D004220:Disulfides; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins; D007096:Imidoesters; D046911:Macromolecular Substances; D008324:Mammary Tumor Virus, Mouse / Q000032:analysis* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008970:Molecular Weight; D013388:Succinimides; D014764:Viral Proteins
chemical_list: D003432:Cross-Linking Reagents; D004220:Disulfides; D006023:Glycoproteins; D007096:Imidoesters; D046911:Macromolecular Substances; D013388:Succinimides; D014764:Viral Proteins; C005905:methyl 4-mercaptobutyrimidate; C011240:dithiobis(succinimidylpropionate)