[Reverse electron transfer in mitochondria of the yeast Endomyces magnusii grown on sucrose]

Some specific features of cytosol-mitochondria interactions during the growth of the Endomyces magnusii yeast on sucrose media were investigated. Under the given experimental conditions exogenous (cytoplasmic) NADH is the main source of reducing equivalents. Using low temperature EPR spectroscopy, it was demonstrated that exogenous NADH can effectively induce reverse electron transfer in the respiratory chain of the yeast. Fluorimetric assays suggest that End. magnusii mitochondria can utilize the reducing equivalents formed by reverse electron transfer for the reductive amination of alpha-ketoglutarate to form glutamate. The intramitochondrial localization of aminotransferases was postulated.