Electron transfer complexes of Ascaris suum muscle mitochondria: I. Characterization of NADH-cytochrome c reductase (complex I-III), with special reference to cytochrome localization.
An NADH-cytochrome c reductase (complex I-III) was isolated from Ascaris suum muscle mitochondria. The enzyme preparation catalyzed the reduction of 1.68 mumol cytochrome c min-1 mg-1 protein at 25 degrees C with NADH but not with NADPH, and retained its sensitivity to rotenone, piericidin A and 2-heptyl-4-hydroxyquinoline-N-oxide as with the submitochondrial particles. The isolated complex I-III, essentially free of succinate-cytochrome c reductase and cytochrome c oxidase, consisted of fourteen polypeptides with apparent molecular weights ranging from 76 000 to 12 000. The complex I-III contained three cytochromes, b-559.5, b-563 and c1-550.5 and Pigment-558 at concentrations of 1.28, 0.211, 1.23 and 0.321 nmol mg-1 protein, respectively. Cytochrome b-558, a major constituent cytochrome of Ascaris mitochondria and previously suggested to participate in the fumarate reductase system, was not fractionated in the complex I-III. Localization of the cytochromes in Ascaris electron transfer complexes is discussed.
D000818:Animals; D001200:Ascaris / Q000201:enzymology*; D003579:Cytochrome Reductases / Q000032:analysis*; D003580:Cytochromes / Q000032:analysis*; D004579:Electron Transport; D008931:Mitochondria, Muscle / Q000201:enzymology*; D009245:NADH Dehydrogenase / Q000032:analysis* / Q000037:antagonists & inhibitors; D010860:Pigments, Biological / Q000032:analysis; D011506:Proteins / Q000032:analysis
D003580:Cytochromes; D010860:Pigments, Biological; D011506:Proteins; D003579:Cytochrome Reductases; D009245:NADH Dehydrogenase