The Reduction and Oxidation of Glutathione by Plant Mitochondria

Abstract

Reduction of oxidized glutathione has been coupled to the oxidation of Krebs cycle intermediates in the presence of plant mitochondria. Oxidation of reduced glutathione by molecular oxygen is catalyzed by mitochondria in the presence of catalytic amounts of ascorbic acid due to the presence of ascorbic acid oxidase. Therefore, a mechanism exists in plant mitochondria for the transfer of hydrogen from Krebs cycle substrates through pyridine nucleotides, glutathione, and ascorbic acid to O2. Such a mechanism does not involve the participation of cytochromes. Attempts to demonstrate oxidative phosphorylation during the reduction of oxidized glutathione and ascorbic acid were negative.