2020
Volume 20, Number 1, pp. 37-40
Chloride anion-activated ATPase
S. Dzneladze, L. Tsakadze, E. Nozadze, L. Shioshvili, M. Leladze, N. Arutinova, T. Jariashvili, S. Kupradze and G. Chkadua
Ivane Beritashvili Centre of Experimental Biomedicine, 14 Gotua St, Tbilisi, Georgia
Plasma membranes of cells contain Cl--activated Mg2+-dependent ATPase, an enzyme with basal MgATPase activity inducible by Cl- ions. Biochemical investigations of Cl--activated MgATPase and MgATP-dependent Cl- transport in different membrane systems suggest that this enzyme is an ATP-dependent Cl- pump involved in active Cl- transport against the electrochemical gradient. The goal of the present work was to elucidate the molecular mechanism of Cl-ATPases. Kinetic investigation has revealed: (1) the MgATP complex is the substrate of the enzymatic reaction; (2) the V = f([Cl-]), where V is reaction velocity, curve is bell-shaped; (3) the number of sites for essential activators and full inhibitors for anion is equal; and (4) during the reaction a phosphorylated intermediate is formed.
Keywords: enzyme kinetics, Chloride-ATPase, P-type ATPase, transport-ATPase