title: Effects of spin-labeled stearates on duck erythrocyte adenylate cyclase.
abstract: The effects of various spin-labeled stearates on duck erythrocyte adenylate cyclase were investigated. Only 2-(3-carboxypropyl)-4,4-dimethyl-2-tridecyl-3-oxazolidinyloxyl caused an increase in adenylate cyclase activity. It increased the basal rate by about 50%, and the activities stimulated by isoproterenol and isoproterenol plus guanosine 5'-[beta,gamma-imido]triphosphate by 35%. Upon analysis of the width parameter delta1 in the electron spin resonance spectra for both the basal enzyme activity and the stimulation obtained with effectors such as guanosine 5'-[beta,gamma-imido]triphosphate, isoproterenol, isoproterenol plus guanosine 5'-[beta,gamma-imido]triphosphate and NaF, a correlation of the changes of modification in adenylate cyclase activities was found. These findings suggest that the molecular environment of the enzyme has been modified.
mesh_terms: D000262:Adenylyl Cyclases / Q000097:blood*; D000818:Animals; D004372:Ducks; D004578:Electron Spin Resonance Spectroscopy; D004910:Erythrocyte Membrane / Q000201:enzymology*; D004912:Erythrocytes / Q000201:enzymology*; D005459:Fluorides / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D013113:Spin Labels; D013228:Stearates / Q000494:pharmacology*; D013229:Stearic Acids / Q000494:pharmacology*
chemical_list: D013113:Spin Labels; D013228:Stearates; D013229:Stearic Acids; D006165:Guanylyl Imidodiphosphate; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D005459:Fluorides