title: [Effect of nucleoside triphosphates on cyclic nucleotide phosphodiesterase: role of protein modulators].
abstract: The effects of nucleoside triphosphates (ATP and GTP) on phosphodiesterase (PDE) of brain and outer segments of the retina enriched or devoid of protein modulators were studied. In the case of retinal outer segment PDE the enzyme activity was considerably inhibited by both nucleosides only when the enzyme was separated from the inhibitor. In case of brain PDE, on the contrary, the effect of the nucleosides was much more pronounced in the enzyme preparation coupled with the protein activator, calmodulin. The latter when added to brain PDE devoid of the activator in the presence of ATP and GTP considerably reduced the enzyme activity. An addition of the inhibitor simultaneously with GTP to the purified PDE of outer segments increased the PDE activity. The constants for the inhibition of brain PDE coupled with calmodulin and retinal outer segment PDE separated from the inhibitor by ATP and GTP were determined.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002135:Calcium-Binding Proteins / Q000502:physiology*; D002147:Calmodulin / Q000502:physiology*; D002417:Cattle; D006160:Guanosine Triphosphate / Q000494:pharmacology*; D007700:Kinetics; D010786:Photoreceptor Cells / Q000201:enzymology*; D012374:Rod Cell Outer Segment / Q000201:enzymology*
chemical_list: D002135:Calcium-Binding Proteins; D002147:Calmodulin; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D015106:3',5'-Cyclic-GMP Phosphodiesterases
vernacular_title: Vliianie nukleozidtrifosfatov na fosforiésterazu tsiklicheskikh nukleotidov; rol' belkovykh moduliatorov.