Effect of bicarbonate and oxaloacetate on malate oxidation by spinach leaf mitochondria

摘要: Abstract Mitochondria isolated from spinach leaves oxidized malate by both a NAD + -linked malic enzyme and dehydrogenase. In the presence of sodium arsenite accumulation oxaloacetate pyruvate during oxidation was strongly dependent on concentration, pH in reaction medium metabolic state condition. Bicarbonate, especially at alkaline pH, inhibited decarboxylation vitro vivo. Analysis products showed that with 15 mM bicarbonate, leaf mitochondria excreted almost exclusively oxaloacetate. The inhibition data were interpreted as indicating that: (a) concentration sides inner mitochondrial membrane governed efflux influx oxaloacetate; (b) /NADH ratio played an important role regulating plant mitochondria; (c) enzymes (malate dehydrogenase enzyme) competing level pyridine nucleotide pool, (d) provided NADH for reversal catalyzed