Short-term regulation of the alpha-ketoglutarate dehydrogenase complex by energy-linked and some other effectors.
The question of regulation of alpha-ketoglutarate dehydrogenase complex (KGDHC) has been considered in the biochemical literature very rarely. Moreover, such information is not usually accurate, especially in biochemical textbooks. From the mini-review of research works published during the last 25 years, the following basic view is clear: a) animal KGDHC is very sensitive to ADP, P(i), and Ca2+; b) these positive effectors increase manifold the affinity of KGDHC to alpha-ketoglutarate; c) KGDHC is inhibited by ATP, NADH, and succinyl-CoA; d) the ATP effect is realized in several ways, probably mainly via opposition versus ADP activation; e) NADH, besides inhibiting dihydrolipoamide dehydrogenase component competitively versus NAD+, decreases the affinity of alpha-ketoglutarate dehydrogenase to substrate and inactivates it; f) thioredoxin protects KGDHC from self-inactivation during catalysis; g) bacterial and plant KGDHC is activated by AMP instead of ADP. These main effects form the basis of short-term regulation of KGDHC.
Strumilo
S
S
Department of Animal Biochemistry, Institute of Biology, University of Bialystok, Bialystok, 15-950, Poland. sstrum@uwb.edu.pl
D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D004734:Energy Metabolism / Q000502:physiology*; D006801:Humans; D007655:Ketoglutarate Dehydrogenase Complex / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism*; D009243:NAD / Q000378:metabolism / Q000494:pharmacology
D009243:NAD; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D007655:Ketoglutarate Dehydrogenase Complex; D002118:Calcium