Ubiquinone-1 induces external deamino-NADH oxidation in potato tuber mitochondria

• Published in: Plant physiology (Bethesda) Vol. 112; no. 1; pp. 75 - 78
• Main Authors: Moller, I.M. (Lund Univ., Lund, Sweden.), Roberts, T.H, Rasmusson, A.G
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Physiologists 01.09.1996
• Subjects: ACTIVIDAD ENZIMATICA; ACTIVITE ENZYMATIQUE; Biochemistry and Molecular Biology; Bioenergetics; Biokemi och molekylärbiologi; Biologi; Biological and medical sciences; Biological Sciences; Cell structures and functions; COENZIMAS; COENZYME; Dehydrogenases; Electron transport chain; Enzymes; Fundamental and applied biological sciences. Psychology; Membrane potential; Metabolism; Mitochondria; Mitochondria and cell respiration; Mitochondrial membranes; MITOCHONDRIE; MITOCONDRIA; Molecular and cellular biology; Natural Sciences; Naturvetenskap; NUCLEOTIDE; NUCLEOTIDOS; OXIDACION; Oxidation; OXIDORREDUCTASAS; OXIRREDUCION; OXYDATION; OXYDOREDUCTASE; OXYDOREDUCTION; PERMEABILIDAD; PERMEABILITE; Photosynthesis, respiration. Anabolism, catabolism; Plant physiology and development; QUINONAS; QUINONE; Quinones; ROTENONA; ROTENONE; SOLANUM TUBEROSUM; Submitochondrial particles; TUBERCULE; TUBERCULO; Tubers; Calcium; Enzyme; Solanum tuberosum; Permeability; Mitochondria; Regulation(control); NADH; Ubiquinone; Dicotyledones; Angiospermae; Tuber; Isolation; Spermatophyta; Oxidation; Oxidoreductases; Tuber plant; Solanaceae; Membrane potential; NADH dehydrogenase (ubiquinone)
• ISSN: 0032-0889; 1532-2548
• DOI: 10.1104/pp.112.1.75

The addition of ubiquinone-1 (UQ-1) induced Ca2+-independent oxidation of deamino-NADH and NADH by intact potato (Solanum tuberosum L. cv Bintje) tuber mitochondria. The induced oxidation was coupled to the generation of a membrane potential. Measurements of NAD+-malate dehydrogenase activity indicated that the permeability of the inner mitochondrial membrane to NADH and deamino-NADH was not altered by the addition of UQ-1. We conclude that UQ-1-induced external deamino-NADH oxidation is due to a change in specificity of the external rotenone-insensitive NADH dehydrogenase. The addition of UQ-1 also induced rotenone-insensitive oxidation of deamino-NADH by inside-out submitochondrial particles, but whether this was due to a change in the specificity of the internal rotenone-insensitive NAD(P)H dehydrogenase or to a bypass in complex I could not be determined