A 1H NMR study of succinate synthesis from exogenous precursors in oxygen-deprived rat heart mitochondria.
Succinate synthesis from exogenous malate, alpha-ketoglutarate, oxaloacetate and L-glutamate in isolated oxygen-deprived rat heart mitochondria was studied using 1H NMR. The highest rate of succinate synthesis was observed during incubation of mitochondria with a mixture of L-glutamate and oxaloacetate. When mitochondria were incubated with [U-13C] glutamate and oxaloacetate the [U-13C] succinate/succinate and aspartate/succinate ratios were equal to 2. This suggests that the succinate produced from [U-13C] alpha-keto-glutarate formed via transamination of [U-13C] glutamate with oxaloacetate by aspartate aminotransferase exceeds twofold that synthesized via oxaloacetate reduction. It may thus be expected that GTP yield in a reaction catalyzed by the succinic thiokinase will be 2 times higher that of ATP production coupled with NADH-dependent fumarate reduction.
Pisarenko
O I
OI
Khlopkov
V N
VN
Ruuge
E K
EK
D000693:Anaerobiosis; D000818:Animals; D005971:Glutamates / Q000378:metabolism; D018698:Glutamic Acid; D007656:Ketoglutaric Acids / Q000378:metabolism; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008293:Malates / Q000378:metabolism; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism*; D010071:Oxaloacetates / Q000378:metabolism; D011048:Polarography; D051381:Rats; D011919:Rats, Inbred Strains; D013386:Succinates / Q000096:biosynthesis*
D005971:Glutamates; D007656:Ketoglutaric Acids; D008293:Malates; D010071:Oxaloacetates; D013386:Succinates; D018698:Glutamic Acid; C030298:malic acid