Quantitative control analysis of branched-chain 2-oxo acid dehydrogenase complex activity by feedback inhibition.
The potential for branched-chain 2-oxo acid dehydrogenase complex (BCOADC) activity to be controlled by feedback inhibition was investigated by calculating the Elasticity Coefficients for several feedback inhibitors. We suggest that feedback inhibition is a quantitatively important regulatory mechanism by which branched-chain 2-oxo acid dehydrogenase activity is regulated. The potential for control of enzyme activity is greater for NADH than for the acyl-CoA products, and suggests that factors that alter the redox potential may physiologically regulate BCOADC activity through a feedback inhibitory mechanism in vivo. Local pH may also be an important regulatory control factor.
Boyer
B
B
Louisiana State University Medical Center, Department of Physiology, New Orleans 70112.
Odessey
R
R
D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide); D000105:Acetyl Coenzyme A / Q000494:pharmacology; D000214:Acyl Coenzyme A / Q000494:pharmacology; D000597:Amino Acids, Branched-Chain / Q000378:metabolism; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D005246:Feedback; D006706:Homeostasis; D006863:Hydrogen-Ion Concentration; D007658:Ketone Oxidoreductases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008928:Mitochondria / Q000201:enzymology; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D009243:NAD / Q000494:pharmacology; D010084:Oxidation-Reduction; D051381:Rats
D000214:Acyl Coenzyme A; D000597:Amino Acids, Branched-Chain; D009097:Multienzyme Complexes; D009243:NAD; C010667:acetoacetyl CoA; D000105:Acetyl Coenzyme A; D007658:Ketone Oxidoreductases; D042942:3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)