title: Purification and characterization of a 43-kDa rotenone-insensitive NADH dehydrogenase from plant mitochondria.
abstract: A 43-kDa NAD(P)H dehydrogenase was purified from red beetroot mitochondria. An antibody against this dehydrogenase was used in conjunction with the membrane-impermeable protein cross-linker 3,3'-dithiobis(sulfosuccinimidylpropionate) to localize the dehydrogenase on the matrix side of the inner membrane. Immunoblotting showed that the dehydrogenase was found in mitochondria isolated from several plant species but not from rat livers. Antibodies against the purified dehydrogenase partially inhibited rotenoneinsensitive internal NADH oxidation by inside-out submitochondrial particles. The level of rotenone-insensitive respiration with NAD-linked substrates correlated with the amount of 43-kDa NAD(P)H dehydrogenase present in mitochondria isolated from different soybean tissues. Based on these results, we conclude that the 43-kDa NAD(P)H dehydrogenase is responsible for rotenone-insensitive internal NADH oxidation in plant mitochondria.
authors.affiliation: Division of Biochemistry and Molecular Biology and the Co-operative Research Centre for Plant Science, The Australian National University, Canberra, ACT 0200, Australia.
authors.forename: R I
authors.initials: RI
authors.lastname: Menz
authors.forename: D A
authors.initials: DA
authors.lastname: Day
mesh_terms: D000818:Animals; D042967:Electron Transport Complex I; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology*; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D010084:Oxidation-Reduction; D018517:Plant Roots / Q000201:enzymology; D010944:Plants / Q000201:enzymology*; D051381:Rats; D012402:Rotenone / Q000494:pharmacology*; D013025:Glycine max / Q000201:enzymology; D013045:Species Specificity; D013367:Submitochondrial Particles / Q000201:enzymology; D013379:Substrate Specificity; D014018:Tissue Distribution; D014475:Uncoupling Agents / Q000494:pharmacology*; D014675:Vegetables / Q000201:enzymology
chemical_list: D008565:Membrane Proteins; D014475:Uncoupling Agents; D012402:Rotenone; D009243:NAD; D009247:NADH, NADPH Oxidoreductases; D042967:Electron Transport Complex I