Acetyl-coenzyme A and coenzyme A analogues. Their effects on rat brain choline acetyltransferase

Publisher Website
Google Scholar
Abstract
Choline acetyltransferase [EC 2.3.1.0] has the same affinity for acetyl-CoA, propionyl-CoA and butyryl-CoA (Km = 1.4 .mu.M). Choline acetyltransferase may use the 2 latter compounds as substrate, but the longer the acyl chain the lower will be Vmax. CoA is an inhibitor (Ki = 1.8 .mu.M). The position of the 3''-phosphate is of primary importance. Desphospho-CoA is a weak inhibitor (Ki = 500 .mu.M). 5''-AMP is already an inhibitor (Ki = 2500 .mu.M). Phosphopantetheine is not an inhibitor. Dextran Blue is a potent inhibitor (Ki = 0.05 .mu.M). Choline acetyltransferase binds to hydrophobic affinity columns. Because of its affinity for nucleotides, affinity for Dextran Blue and hydrophobicity, it probably contains the nucleotide fold, which is a common structural domain present in several enzymes binding nucleotides.