Affinity labeling of the (Na+ + Mg2+)-ATPase from Acholeplasma laidlawii B membranes by the 2',3'-dialdehyde derivative of adenosine 5'-triphosphate.
The (Na+ + Mg2+)-ATPase of the Acholeplasma laidlawii B plasma membrane was inactivated by the 2',3'-dialdehyde derivative of ATP (oATP). oATP behaved as a reversible competitive inhibitor of this ATPase and was slowly hydrolyzed by the enzyme. In addition, oATP induced an irreversible inactivation of the enzyme. A 62% inactivation of the enzyme correlated with the binding of 16 moles of oATP per mole of the enzyme. In the presence of 5'-adenylyl imidodiphosphate, a non-hydrolyzable substrate analogue, the stoichiometry was 8 moles oATP per mole of ATPase. By SDS-polyacrylamide gel electrophoresis, [U-14C]oATP was found to bind covalently to four of the five subunits of the enzyme, but specific labeling was highest for the gamma-subunit of the ATPase.
George
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McElhaney
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D000128:Acholeplasma laidlawii / Q000201:enzymology*; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D000345:Affinity Labels / Q000494:pharmacology; D001667:Binding, Competitive; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics
D000345:Affinity Labels; D000266:Adenylyl Imidodiphosphate; C017199:2',3'-dialdehyde ATP; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C035123:magnesium sodium ATPase