Membrane protein and glycoprotein composition of beef brain synaptic vesicles.
Synaptic vesicles were isolated from adult bovine cortical gray matter by differential centrifugation and membrane filtration of a hypoosmotically lysed crude mitochondrial fraction. Vesicle preparations were analyzed for purity by electron microscopy and enzyme assays. Polyacrylamide gel electrophoresis of SDS-solubilized and 2-mercaptoethanol-reduced vesicle membrane proteins revealed 4 major proteins with molecular weights ranging from 17,000 to 60,000, and about 10 minor proteins with molecular weights up to 170,000. The protein profile of the Triton X-100-extracted vesicle membranes was less complex, with 1 major protein and 5 minor bands. The major protein of the Triton extract was identified as a glycoprotein with a molecular weight of 45,000. Two additional minor PAS-positive bands were seen, with molecular weights of 78,000 and 95,000.
D000818:Animals; D001921:Brain / Q000201:enzymology; D001923:Brain Chemistry; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000032:analysis*; D008565:Membrane Proteins / Q000032:analysis*; D008854:Microscopy, Electron; D008970:Molecular Weight; D011092:Polyethylene Glycols; D013570:Synaptic Membranes / Q000032:analysis*; D013572:Synaptic Vesicles / Q000032:analysis* / Q000201:enzymology
D006023:Glycoproteins; D008565:Membrane Proteins; D011092:Polyethylene Glycols