Reactivation of the NADH-Q1 reductase activity of the isolated rotenone-insensitive NADH dehydrogenase of Arum maculatum mitochondria. Activation of quinone reductase activity by a hydrophobic component extractable from Arum mitochondrial membranes

Abstract

The rotenone-insensitive NADH dehydrogenase of Arum maculatum mitochondria is inactivated during the process of purification. The ubiquinone reductase activity is inactivated while the dichlorophenolindophenol (DCIP) reductase activity is not. The former activity can be largely restored by an ether-extractable component(s) from Arum mitochondrial membranes which co-purifies with the enzyme. Thin-layer chromatography showed that the component responsible for maintaining ubiquinone reductase activity co-purifies with the enzyme and is not ubiquinone-10 or phosphotidyl choline. Up to 80% of the original activity was restored by the ether extract. These observations show that the rotenone-insensitive NADH dehydrogenase, inactivated during purification can be reactivated after the isolation process.