ISSN:
1399-3054
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Biologie
Notizen:
The possible existence of a malonate-sensitive dicarboxylate-mediated electron shuttle between microsomal NAD-linked fatty acid α-oxidation and the mitochondrial electron transport chain in uncoupled fresh potato slices was investigated. Uncoupled slice respiration is inhibited by benzylmalonate and butylmalonate, inhibitors of dicarboxylate transport into mitochondria. Uncoupled slice respiration is also inhibited by rotenone, an indication of intramitochondrial NADH oxidation. Since fatty acid α-oxidation per se is rotenone insensitive, rotenone and benzylmalonate inhibition of the oxidation of carboxyl-labeled myristate in slices points to a dicarboxylic acid shuttle linking microsomal fatty acid a-oxidation with intramitochondrial NADH dehydrogenase.Malonute inhibits both respiration and 14CO2, release from carboxyl-labeled myristate in fresh uncoupled slices, as do inhibitors of dicarboxylate transport. Mitochondrial studies show that malonate inhibits malate oxidation but not malate dehydrogenase per se. Furthermore, malonate inhibits malate transport more severely than malate oxidation. Accordingly, mulonate inhibition of uncoupled slice respiration in the absence of tricarboxylic acid cycle activity is attributed to its interference with mitochondrial malate transport, and its consequent curtailment of a putative malate-OAA shuttle linked to cytosolic NAD-mediated fatty acid α-oxidation.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1399-3054.1983.tb04147.x
Permalink