ADP-arsenate. Formation by submitochondrial particles under phosphorylating conditions

Abstract

Submitochondrial particles from beef heart mitochondria synthesize ADP-arsenate from ADP and arsenate when energized by succinate. The ADP-arsenate formed hydrolyzes rapidly and this is almost certainly the mechanism by which arsenate "uncouples" oxidative phosphorylation. When sufficient hexokinase is present, a substantial portion of the ADP-arsenate formed reacts with glucose to form glucose 6-arsenate and ADP. The glucose 6-arsenate thus formed hydrolyzes, at pH 7.5 and 30 degrees C, under the conditions used, with a rate constant of 5.5 X 10(-4) s-1 and is a substrate for glucose-6-phosphate dehydrogenase.