[Influence of effectors of hormone-sensitive adenylate cyclase on the activation system of photostimulated cyclic nucleotide phosphodiesterase from outer rod segments].
The effect of preincubation of preparations of the outer segments of optic rods with the nonhydrolyzed analog GTP-guanilyl-5'-imidodiphosphate (Gpp(NH)p) and NaF, the combined effect of these agents as well as the action of (NH4)2SO4 (10-800 mM), MgSO4 (2-50 mM) and induction of peroxide oxidation of lipids are studied as applied to the catalytic activity of phosphodiesterase of cyclic nucleotides. Gpp(NH)p and NaF are shown to be tightly bound to GTP-binding proteins (G-proteins) of outer segments of optic rods, additional activation of phosphodiesterase in the presence of Gpp(NH)p being observed after preincubation with NaF and subsequent washing of the membrane. A problem on different binding sites of the ion F and Gpp(NH)p on G-proteins is discussed. It is found that (NH4)2SO4 does not affect the basal activity of phosphodiesterase but inhibits the activating effect of Gpp(NH)p and NaF on the enzyme. Induction of peroxide oxidation of lipids prevented by the addition of ionol (antioxidant) in a dose of 5.10(-4) M has the same effect. Changes in the concentration of Mg2+ in the medium influence insignificantly the basal activity of phosphodiesterase but are necessary for manifestation of the activating effect of Gpp(NH)p and NaF.
D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000645:Ammonium Sulfate / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D004789:Enzyme Activation / Q000187:drug effects; D005136:Eye Proteins / Q000378:metabolism*; D020558:GTP Phosphohydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D020962:Heterotrimeric GTP-Binding Proteins; D066298:In Vitro Techniques; D008054:Lipid Peroxides / Q000378:metabolism; D008278:Magnesium Sulfate / Q000494:pharmacology; D010775:Photic Stimulation; D010786:Photoreceptor Cells / Q000201:enzymology*; D011896:Rana temporaria; D012374:Rod Cell Outer Segment / Q000201:enzymology*; D012969:Sodium Fluoride / Q000494:pharmacology; D015293:Transducin
D005136:Eye Proteins; C034809:GNAT1 protein, human; D008054:Lipid Peroxides; D006165:Guanylyl Imidodiphosphate; D008278:Magnesium Sulfate; D012969:Sodium Fluoride; D015087:2',3'-Cyclic-Nucleotide Phosphodiesterases; D020558:GTP Phosphohydrolases; D020962:Heterotrimeric GTP-Binding Proteins; D015293:Transducin; D000262:Adenylyl Cyclases; D000645:Ammonium Sulfate
Vliianie éffektorov gormonchuvstvitel'noĭ adenilattsiklazy na sistemu aktivatsii fotostimuliruemoĭ fosfodiesterazy tsiklicheskikh nukleotidov v naruzhnykh segmentakh palochek setchatki.