title: NADH-ubiquinone oxidoreductase activity in the kinetoplasts of the plant trypanosomatid Phytomonas serpens.
abstract: NADH-ubiquinone oxidoreductase activity is present in mitochondrial lysates of Phytomonas serpens. Rotenone at 2-10 microM inhibited the activity 50-75%, indicating that it belongs to respiratory complex I. The activity was also inhibited 50-60% in the presence of 10-30 nM atovaquone suggesting that inhibition of complex I represents a likely mechanism of the known antileishmanial activity of this drug. The complex was partially purified by chromatography on DEAE-Sepharose CL-6B and gel-filtration on Sepharose CL-2B. The NADH:ubiquinone oxidoreductase activity in this preparation was completely inactivated by 20 nM atovaquone. The partially purified complex was present in a low amount and its subunits could not be discerned by staining with Coomassie. However, one of its components, a homologue of the 39 kDa subunit of the bovine complex I, was identified immunochemically in the original lysate and in the partially purified material.
authors.affiliation: Department of Biology, University of California, 3401 Watkins Drive, Riverside, CA 92521, USA.
authors.forename: Diego
authors.initials: D
authors.lastname: González-Halphen
authors.forename: Dmitri A
authors.initials: DA
authors.lastname: Maslov
mesh_terms: D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology; D053626:Atovaquone; D015153:Blotting, Western; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004579:Electron Transport; D042967:Electron Transport Complex I / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D008928:Mitochondria / Q000201:enzymology*; D024101:Mitochondrial Proteins / Q000302:isolation & purification / Q000378:metabolism; D009285:Naphthoquinones / Q000494:pharmacology; D010084:Oxidation-Reduction; D021122:Protein Subunits / Q000737:chemistry; D012402:Rotenone / Q000494:pharmacology; D014351:Trypanosomatina / Q000201:enzymology*; D014475:Uncoupling Agents / Q000494:pharmacology
chemical_list: D000981:Antiprotozoal Agents; D024101:Mitochondrial Proteins; D009285:Naphthoquinones; D021122:Protein Subunits; D014475:Uncoupling Agents; D012402:Rotenone; D042967:Electron Transport Complex I; D053626:Atovaquone