Sergey A. Menzikov

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The influence of the GABA on the Mg(2+)-ATPase from microsomal fraction of fish brain (Abramis brama L.) was investigation. Preincubation of the microsomes with different concentration of GABA (10(-8)-10(-4) M) stimulated Mg(2+)-ATPase activity. This effect of neuromediator is sensitive to picrotoxine (10(-4) M). It was established that Mg(2+)-ATPase(More)
We studied the effect of Cl− (10–75 mM) and $$ {\text{HCO}}_3^{-} $$ ions (10–25 mM) on the ATP-dependent GABAA receptor-coupled Cl− channel (Cl−-ATPase) in rat brain plasma membranes. The total enzyme activity was detected in the presence of both anions at a Cl−/ $$ {\text{HCO}}_3^{-} $$ ratio of 5:1 (Cl−, $$ {\text{HCO}}_3^{-} $$ -ATPase). Specific(More)
Action of Cl− + HCO3 −1 ions on Mg2+-ATPase from brain plasma membranes of fish and rats has been studied. Maximal effect of the anions on the “basal” Mg2+-ATPase activity is revealed in the presence of 10 mM Cl− and 3 mM HCO3 −1 at physiological values of pH of incubation medium. The studied Cl−, HCO3 −-activated Mg2+-ATPases of both animal species, by(More)
Phosphorylation of the sensitive to GABA(A)-ergic ligands Cl-, HCO3--stimulated Mg2+-ATPase of the plasma membranes from fish brain by [gamma-32P]ATP was investigated in the presence of Mg2+. It was established, that formation of the phosphoprotein at 0-1 degrees C is dependent on time incubation and concentration of Mg2+ in the incubation medium.(More)
Effect of Cl and HCO3- ions on the Mg2+ -ATPase activity of the plasma membrane of bream brain was investigated. Cl- (5 or 10 mM) and HCO3- (1-5 mM) individually have low effect on the "basal" Mg2+ -ATPase. Simultaneous presence of Cl- and HCO3- in the incubation medium significantly increased the enzyme activity. Maximum effect of anions on the enzyme is(More)
A Cl−, HCO 3 − -ATPase isolated from the plasma membranes of fish brain was reconstituted in artificial proteoliposomes. The original sensitivity to GABAA-ergic ligands was preserved in the reconstituted enzyme. GABA was shown to activate the liposome-embedded enzyme in a concentration range from 10 to 100 μM while picrotoxin (100 μM) removed this(More)
64 Cl – , -Activated Mg 2+ -ATPase from plasma membranes of fish brain is a candidate for the role of an ATPase system coupled to GABA receptors and involved in ATP-dependent Cl – / exchange [1, 2]. With respect to some biochemical parameters (molecular weight, subunit composition, sensitivity to blockers of ligand-gated Cl – -channels, etc.), this enzyme(More)
In plasma membranes of the fish brain, we found a Cl – stimulated Mg 2+ ATPase whose “basal” Mg 2+ ATPase activity was stimulated by Cl – -ions (Cl − ATPase) [1]. The properties of this enzyme differed significantly from those of the Cl – ATPase (Cl − pump) in the mammalian (rat) brain [2]. In particular, the two enzymes differed in the pH optimum, ä å of(More)
The interaction between mediators at low concentrations and GABA Ä /benzodiazepine receptor complex on the postsynaptic membrane, accompanied by conformational changes in the Cl – -channel and an increase in neuronal Cl – -current and leading to membrane hyperpolarization and a decrease in neuronal excitability, has been described in the literature [1].(More)