Identical properties of transmembrane synaptic vesicle protein M(r) 100,000 in Torpedo and M(r) 86,000 in bovine...

Synaptic vesicles derived from the Torpedo electric organ and bovine cerebral cortex contain concanavalin A binding transmembrane glycoproteins of M(r) 100,000 and 86,000, respectively. Their isolelectric points range from 5.5 to 6.0. On deglycosilation both glycoproteins yield identical products of M(r) 62,000. The fully glycosilated and the deglycosilated proteins from both Torpedo and bovine brain are recognized by the monoclonal anti-SV2 antibody (Buckley and Kelly, J. Cell Biol.100, 1284-1294, 1985) as well as by a monospecific IgG fraction raised against Torpedo vesicles and immunopurified against the bovine brain M(r) 86,000 glycoprotein. This is shown by Western blotting as well as by immunoaffinity isolation with one antibody and immunodetection with the other antibody. Furthermore on immunohistochemical analysis of the Torpedo electric organ both antibodies recognize exactly the same nerve terminal ramifications. It is concluded that the glycoproteins of M(r) 100,000 in Torpedo and of M(r) 86,000 in bovine brain are corresponding proteins with different degrees of glycosilation.