Reverse electron transfer in mitochondria of the yeast Endomyces magnusii grown on glycerol
Zelenshchikova, V.A.; Burbaev, D.Sh.; Zviagil'skaia, R.A.
Biokhimiia 48(2): 186-192
1983
ISSN/ISBN: 0320-9725 PMID: 6838918 Document Number: 210954
Some cytosol-mitochondria interactions during the growth of E. magnusii on glycerol media were studied. Under the experimental conditions the main reducing equivalent donors are exogenous NADH and .alpha.-glycerophosphate. Using 2 independent methods, i.e., fluorimetric assay and low temperature EPR spectroscopy, it was demonstrated that these substrates are most effective in reverse electron transfer in the respiratory chain. The involvement of intramitochondrial NADPH formed by oxidation of .alpha.-glycerophosphate in glutamate synthesis is postulated. Possible causes of diverse effects of flavin-dependent substrates, i.e., exogenous NADH, .alpha.-glycerophosphate and succinate, on the induction of reverse electron transfer are discussed. The regulation of this process by an alternative oxidative pathway is suggested.