TY - JOUR T1 - Kinetics of Oligomycin Inhibition of Sodium- and Potassium-Activated Adenosine Triphosphatase from Beef Brain JF - Molecular Pharmacology JO - Mol Pharmacol SP - 591 LP - 599 VL - 4 IS - 6 AU - CHARLES E. INTURRISI AU - ELWOOD TITUS Y1 - 1968/11/01 UR - http://molpharm.aspetjournals.org/content/4/6/591.abstract N2 - Oligomycin and rutamycin inhibited the activity of a beef brain adenosine triphosphatase that required both sodium and potassium, but these antibiotics were without effect on the potassium-requiring p-nitrophenyl phosphatase or acetyl phosphatase obtained from the same preparation. Several other macrolide antibiotics believed to be structurally similar to oligomycin were without appreciable effect on either the adenosine triphosphatase or the p-nitrophenyl phosphatase. Kinetic studies indicated that oligomycin is an uncompetitive inhibitor of the sodium- and potassium-requiring adenosine triphosphatase. The antibiotic was an uncompetitive inhibitor of sodium activation and a noncompetitive inhibitor of the potassium activation of this enzyme. Alteration of the Mg++: ATP ratio from 0.1 to 5.0 did not affect the inhibition by oligomycin. It would appear that oligomycin is an even more selective inhibitor than the cardiac glycosides of the hydrolytic function that requires both sodium and potassium. ER -