title: Crayfish abdominal muscle adenylate cyclase. Studies on the stimulation by a Ca2+-binding protein.
abstract: A plasma-membrane preparation of crayfish muscle showed an adenylate cyclase activity which is inhibited to about 80% of its original activity by 100 microM-EGTA. Measurements of the enzyme activity in the presence of 100 microM-EGTA and various concentrations of Ca2+ revealed an increase in enzyme activity of about 400%, indicating an adenylate cyclase which is dependent on Ca2+ for activity. Fluphenazine (1 mM), a blocker of the Ca2+-binding protein calmodulin, decreased enzyme activity to zero. The enzyme can be re-activated by the addition of certain concentrations of calmodulin to the assay medium. This suggests that crayfish muscle adenylate cyclase is dependent on Ca2+ and calmodulin for activity.
mesh_terms: D000009:Abdominal Muscles / Q000201:enzymology*; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D003400:Astacoidea / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000494:pharmacology*; D002147:Calmodulin / Q000494:pharmacology*; D002462:Cell Membrane / Q000201:enzymology; D004533:Egtazic Acid / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005476:Fluphenazine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male
chemical_list: D000067956:Adenylyl Cyclase Inhibitors; D002135:Calcium-Binding Proteins; D002147:Calmodulin; D004533:Egtazic Acid; D000262:Adenylyl Cyclases; D005476:Fluphenazine; D002118:Calcium