Principato G B, Gabriella R, Virginia B, Elvio G
Biochem Int. 1984 Jan;8(1):135-41.
Horse serum Cholinesterase hydrolyzes choline and p-nitrophenol esters at different rates. Deacylation and acylation seem to be the rate-limiting step for charged and uncharged substrates respectively. Activation energy is similar for the acetic, propionic, and butyric esters of thiocholine, but it is higher for p-nitrophenylpropionate. Inhibition by the tetramethyl-ammonium ion is competitive. Tetraethyl-, tetrapropyl-, and tetrabutyl-ammonium ions are mixed-type inhibitors. The pH studies demonstrated the existence of a residue, pK = 6.33, involved in catalysis.
马血清胆碱酯酶以不同速率水解胆碱和对硝基苯酚酯。脱酰化和酰化似乎分别是带电荷和不带电荷底物的限速步骤。硫代胆碱的乙酸酯、丙酸酯和丁酸酯的活化能相似，但对硝基苯丙酸酯的活化能更高。四甲基铵离子的抑制作用是竞争性的。四乙基铵离子、四丙基铵离子和四丁基铵离子是混合型抑制剂。pH研究表明存在一个参与催化的残基，其pK = 6.33。
