Chloride-ATPase dephosphorylation in Aplysia gut.
The present study was done primarily to compare cation-ATPase dephosphorylation kinetics with a Cl(-)-ATPase's dephosphorylation kinetics because of the paucity of information in this area. Utilizing a proteoliposomal preparation containing Cl(-)-ATPase from Aplysia gut, it was demonstrated that dephosphorylation of this P-type ATPase was absolutely dependent upon Cl(-). Adenosine triphosphate (ATP) concentrations directly stimulated dephosphorylation of Cl(-)-ATPase in the presence of increasing concentrations of Cl(-). It was also shown that the calculated rate constant for E(1)-P disintegration was 20/sec. This rate constant value approximated E(1)-P rate constant disintegration values for other electrogenic, uniport P-type ATPases. Therefore, it was concluded from these results that the Cl(-)-ATPase dephosphorylation kinetics did not differ greatly from cation-ATPase dephosphorylation kinetics.
Department of Physiology, College of Medicine, University of Florida, Gainesville, Florida 32610, USA.
Georpe A
GA
Gerencser
Jianliang
J
Zhang
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D027321:Anion Transport Proteins; D001048:Aplysia / Q000201:enzymology*; D002712:Chlorides / Q000378:metabolism* / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D019811:Hydroxylamine / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000201:enzymology*; D007700:Kinetics; D010766:Phosphorylation / Q000187:drug effects
D027321:Anion Transport Proteins; D002712:Chlorides; D019811:Hydroxylamine; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C031652:anion-sensitive ATPases