INTERMEDIARY METABOLISM OF LIVER FLUKE FASCIOLA HEPATICA .2. HYDROGEN TRANSPORT AND PHOSPHORYLATION

The reoxidation of NADH derived from glycolysis was studied in the liver fluke Fasciola hepatica. A NADH: fumarate oxidoreductase activity was demonstrated, which was inhibited by various uncoupling agents of the respiratory chain. Although no cytochrome c was detectable in the liver fluke, it proved possible to demonstrate NADH:cytochrome c oxidoreductase and succinate: cytochrome c oxidoreductase with the help of mammalian cytochrome c. The inhibitory action of various uncoupling agents was tested. From these results it is assumed that the hydrogen is transferred from NADH via a flavoprotein to quinone and subsequently via a second flavoprotein to fumarate, giving rise to succinate formation. Furthermore, it was found that the oxidation of NADH was coupled with phosphorylation in a ratio of approximately 1. This phosphorylation reaction was inhibited by the addition of 2,4-di-nitrophenol but not by CN⊖. © 1969, IEEE. All rights reserved.