Acetyl-coenzyme A and coenzyme A analogues. Their effects on rat brain choline acetyltransferase.
Choline acetyltransferase has the same affinity for acetyl-CoA, propionyl-CoA and butyryl-CoA (Km=1.4 micron). Choline acetyltransferase may use the two latter compounds as substrate, but the longer the acyl chain the lower will be Vmax. CoA is an inhibitor (Ki=1.8 micron). The position of the 3'-phosphate is of primary importance. Desphospho-CoA is a weak inhibitor (Ki=500 micron). 5'-AMP is already an inhibitor (Ki=2500 micron). Phosphopantetheine is not an inhibitor. Dextran Blue is a potent inhibitor (Ki=0.05 micron). Choline acetyltransferase binds to hydrophobic affinity columns. Because of its affinity for nucleotides, affinity for Dextran Blue and hydrophobicity, it is proposed that it contains the 'nucleotide fold', which is a common structural domain present in several enzymes binding nucleotides.
D000105:Acetyl Coenzyme A / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000201:enzymology; D055598:Chemical Phenomena; D002621:Chemistry; D002795:Choline O-Acetyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002846:Chromatography, Affinity; D003065:Coenzyme A / Q000031:analogs & derivatives* / Q000378:metabolism; D051381:Rats
D000105:Acetyl Coenzyme A; D002795:Choline O-Acetyltransferase; D003065:Coenzyme A