The role of malate in regulating the rate of mitochondrial respiration in vitro
Vovyleva-Guarriero, V.B.; Wehbie, R.S.; Muscatello, U.; Lardi, G.A.
Biokhimiia 56(3): 542-551
1991
ISSN/ISBN: 0320-9725 PMID: 1883909 Document Number: 380940
Depletion of endogenous malate by preincubation of mitochondria at 30 degrees C in substrate-free media sharply decreases the rate of citrate oxidation and inhibits mitochondrial respiration in the presence of pyruvate and alpha-ketoglutarate. Addition of catalytic amounts of endogenous malate and its production via succinate oxidation promote rapid oxidation of citrate and pyruvate in the mitochondria and abolishes the lag period with alpha-ketoglutarate Malate increases the rate of membrane potential generation after addition of citrate, pyruvate or alpha-ketoglutarate to mitochondrial suspensions. Studies with controlled malate concentrations revealed that the changes in malate concentrations observed in the mitochondria in the presence of gluconeogenesis-inducing hormones may be due to the influence of these hormones on mitochondrial oxidation.