title: Effect of modification of synaptosomal membrane glycoproteins on adenylate cyclase activity.
abstract: The effect of the modification of synaptosomal membrane glycoproteins on the activity of adenylate cyclase was studied. It was found that the binding of concanavalin A to unmodified guinea pig cerebral cortex synaptosomal membrane did not change adenylate cyclase activity. Concanavalin A binding to synaptosomal membrane of hypoxic brain cortex resulted in no decrease of enzyme activity. The level of protein-bound sialic acid in these synaptosomal fractions was 20% lower than in the control. Treatment of synaptosomal membranes with neuraminidase resulted in a decrease of sialic acid content by about 70%, but it had no significant effect on adenylate cyclase activity. The modification with concanavalin A of sugar end groups exposed by neuraminidase treatment resulted in significant decrease of both basal and fluoride-stimulated adenylate cyclase activity. These results seem to indicate that some component of the adenylate cyclase complex of brain synaptosomal membranes is closely interacting with a carbohydrate-containing macromolecule on the cell surface.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D003208:Concanavalin A / Q000494:pharmacology; D006023:Glycoproteins / Q000502:physiology*; D006168:Guinea Pigs; D008565:Membrane Proteins / Q000502:physiology*; D009439:Neuraminidase / Q000494:pharmacology; D011952:Receptors, Concanavalin A / Q000378:metabolism; D012794:Sialic Acids / Q000032:analysis; D013574:Synaptosomes / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D008565:Membrane Proteins; D011952:Receptors, Concanavalin A; D012794:Sialic Acids; D003208:Concanavalin A; D009439:Neuraminidase; D000262:Adenylyl Cyclases