Transaminase reaction rates, transport activities and TCA cycle analysis by post-steady state 13C NMR.
In this work, we present the post-steady state analysis of the TCA cycle and a closed form solution to the rate of label washout from the C4 carbon of glutamic acid through the transaminases and the malate-aspartate shuttle and then through alpha-ketoglutarate dehydrogenase. We demonstrate using a model of this problem that the rate of label washout depends not only on the flux through alpha-ketoglutarate dehydrogenase, but most importantly on the activity of the malate-aspartate shuttle as determined by the forward and reverse fluxes through the transaminases and by the rate of transport of glutamate and alpha-ketoglutarate across the mitochondrial membrane.
Robitaille
P M
PM
Department of Medical Biochemistry, Ohio State University, Columbus 43210.
Rath
D P
DP
Skinner
T E
TE
Abduljalil
A M
AM
Hamlin
R L
RL
D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D002952:Citric Acid Cycle / Q000502:physiology*; D004285:Dogs; D007655:Ketoglutarate Dehydrogenase Complex / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008293:Malates / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D000637:Transaminases / Q000378:metabolism*
D008293:Malates; D001224:Aspartic Acid; D007655:Ketoglutarate Dehydrogenase Complex; D000637:Transaminases