title: Ca2+-dependent regulation of cyclic-AMP phosphodiesterase by parvalbumin.
abstract: Carp parvalbumin has been shown to activate rat brain phosphodiesterase in a Ca2+-dependent manner. The concentration of Ca2+ required for half-maximal stimulation is 1.4 X 10(-7) M, whereas rat testis Ca2+-dependent regulator (CDR) of phosphodiesterase required 1.2 X 10(-6) M Ca2+. The difference in the slopes of the two curves demonstrated that the activation induced by parvalbumin was not the result of a small contamination by CDR. In addition, it has been shown that Ca2+ binding to parvalbumin parallels its activation of phosphodiesterase. These data suggest that Ca2+ must bind to a single specific metal binding site before phosphodiesterase can be fully activated.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000201:enzymology; D002118:Calcium / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D005399:Fishes; D007700:Kinetics; D008297:Male; D009124:Muscle Proteins / Q000494:pharmacology*; D009132:Muscles; D010320:Parvalbumins / Q000494:pharmacology*; D010727:Phosphoric Diester Hydrolases / Q000494:pharmacology*; D011506:Proteins / Q000502:physiology; D051381:Rats; D013737:Testis
chemical_list: D009124:Muscle Proteins; D010320:Parvalbumins; D011506:Proteins; D010727:Phosphoric Diester Hydrolases; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D002118:Calcium