Gerencser G A
Department of Physiology, College of Medicine, University of Florida, Gainesville 32610.
Biochem Biophys Res Commun. 1993 Nov 15;196(3):1188-94. doi: 10.1006/bbrc.1993.2377.
Utilizing a proteoliposomal preparation containing Cl(-)-ATPase, it was demonstrated that [gamma-32P]ATP-induced phosphorylation of this pump is by way of a relatively low binding affinity while protein dephosphorylation was accelerated by increasing concentrations of unlabeled ATP. Ca2+ and Mn2+ were also shown to stimulate phosphorylation of the enzyme, but to a much lesser extent than Mg2+. Orthovanadate inhibition of enzyme phosphorylation was directly related to its concentration. These results suggested that the Cl(-)-pump was a P-type ATPase similar to that found in plants and fungi based upon its low-affinity phosphorylation kinetics.
