Phosphorylation of chloride-ATPase reconstituted from Aplysia gut.
The present study was primarily done to compare cation-ATPase phosphorylation kinetics with an anion-ATPase's phosphorylation kinetics because of the paucity of information in this area. Utilizing a proteolipsomal preparation containing Cl(-)-ATPase from Aplysia gut, it was demonstrated that phosphorylation of this P-type ATPase was absolutely dependent upon Mg(2+). In organic phosphate concentrations directly (P(i)) enhanced phosphoprotein formation in the presence of increasing concentrations of Mg(2+). It was also shown that the calculated rate constant for E(1)-P formation was 26/sec. This approximated E(1)-P rate constant values for other electrogenic, uniport P-type ATPases, and therefore it was concluded from the results that the anion-ATPase phosphorylation kinetics did not greatly differ from cation-ATPase phosphorylation kinetics.
Gerencser
G A
GA
Department of Physiology, College of Medicine, University of Florida, Gainesville, Florida 32610, USA. gag@phys.med.ufl.edu
Zhang
J
J
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D027321:Anion Transport Proteins; D001048:Aplysia / Q000201:enzymology*; D007413:Intestinal Mucosa / Q000201:enzymology*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D010750:Phosphoproteins / Q000032:analysis / Q000096:biosynthesis; D010766:Phosphorylation / Q000187:drug effects
D027321:Anion Transport Proteins; D010750:Phosphoproteins; D000251:Adenosine Triphosphatases; C031652:anion-sensitive ATPases; D008274:Magnesium