Interaction of acetyl-CoA fragments with rat liver acetyl-CoA carboxylase.
The interaction of acetyl-CoA fragments with rat liver acetyl-CoA carboxylase has been studied. Dephosphorylated acetyl-CoA did not actually differ from acetyl-CoA in its substrate properties. Non-nucleotide analogues of the substrate, S-acetylpantatheine and it's 4'-phosphate, also possess substrate properties (Vmax = 1.5% and 15% of the maximal rate value of acetyl-CoA carboxylation, respectively). The nucleotide fragment in the acetyl-CoA molecule produces a marked effect on the thermodynamics of the substrate-enzyme interaction, and is apparently involved in activation and appropriate orientation of the acetyl group in the active site. The better substrate properties of S-acetylpantetheine 4'-phosphate and the inhibitory properties of pantetheine 4'-phosphate, compared to the unphosphorylated analogues, evidence an important role of the 5'-beta-phosphate of 3'-phosphorylated ADP residue in acetyl-CoA binding to the enzyme.
Rabinkov
A G
AG
V.A. Engelhardt Institute of Molecular Biology, USSR Academy of Sciences, Moscow.
Velikodvorskaya
V V
VV
Kopelevich
V M
VM
Tolosa
E A
EA
Gunar
V I
VI
D000105:Acetyl Coenzyme A / Q000378:metabolism*; D000103:Acetyl-CoA Carboxylase / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D010204:Pantetheine / Q000031:analogs & derivatives / Q000494:pharmacology; D010766:Phosphorylation; D011498:Protein Precursors; D051381:Rats; D013379:Substrate Specificity / Q000187:drug effects; D013816:Thermodynamics
D011498:Protein Precursors; D010204:Pantetheine; D000105:Acetyl Coenzyme A; D000103:Acetyl-CoA Carboxylase