Effect of NAD on Malate Oxidation in Intact Plant Mitochondria.
Potato tuber mitochondria oxidizing malate respond to NAD(+) addition with increased oxidation rates, whereas mung bean hypocotyl mitochondria do not. This is traced to a low endogenous content of NAD(+) in potato mitochondria, which prove to take up added NAD(+). This mechanism concentrates NAD(+) in the matrix space. Analyses for oxaloacetate and pyruvate (with pyruvate dehydrogenase blocked) are consistent with regulation of malate oxidation by the internal NAD(+)/NADH ratio.
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Physiologie Cellulaire Végétale, Département de Recherche Fondamentale/BV, CEN-G and USM-G 85 X 38041 Grenoble Cedex France.
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Journet
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Neuburger
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