2012
Volume 12, Number 3, pp. 113–115
Mg-dependent HCO3-ATPase is a P-type transporting ATPase
L. Tsakadze, M. Leladze, S. Dzneladze and Z. Kometiani
I. Beritashvili Centre of Experimental Biomedicine, 14 Gotua St, 0160 Tbilisi, Georgia
Mg2+-dependent HCO3-ATPase’s kinetic peculiarities were studied in synaptosomal membrane fractions of rat brain using the method of kinetic curve analysis. The enzyme satisfies the necessary kinetic conditions of transporting ATPases: (1) the HCO3ion dependence curve is bell-shaped; (2) the MgATP complex constitutes the substrate of the enzymic reaction; (3) the HCO3-ATPase’s substrate dependence curve is identical to those of other “P-type” transporting ATPases. Therefore, it can be inferred that Mg2+-dependent HCO3-ATPase belongs to the group of so-called “P-type” transporting ATPases.
Keywords: synaptosome Mg2+-dependent HCO3-ATPase “P-type” ATPase