粟酒裂殖酵母非特异性酸性磷酸酶催化磷酸酯水解机制的一些动力学方面

Some kinetic aspects of the mechanism of hydrolysis of phosphoric acid esters by nonspecific acid phosphatase from Schizosaccharomyces pombe.

Dibenedetto G, Mura U

Biochim Biophys Acta. 1978 Jan 12;522(1):122-9. doi: 10.1016/0005-2744(78)90328-5.

Abstract

The kinetics of the hydrolysis of nitrophenylphosphate by nonspecific acid phosphatase (orthophosphoric-monoester phosphohydrolase (acid optimum), EC 3.1.3.2.) from Schizosaccharomices pombe was studied. 2. The kinetic parameters, Km and V, were determined as well as the inhibition constants, K1, for the inhibitors, phosphate and fluoride, as a function of pH. 3. The results, interpreted according to the theories of Dixon and Waley indicated the presence of three ionizable groups on the enzyme itself and one on the enzyme-substrate complex. 4. A model of the hydrolysis of phosphoric acid monoesters by the S. pombe acid phosphatase is proposed based on the ionization state of the reactants and on the results of the inhibition by the competitive inhibitors.

摘要

研究了来自粟酒裂殖酵母的非特异性酸性磷酸酶（正磷酸单酯磷酸水解酶（最适酸性条件），EC 3.1.3.2.）催化硝基苯磷酸酯水解的动力学。2. 测定了动力学参数Km和V，以及抑制剂磷酸盐和氟化物的抑制常数K1随pH的变化情况。3. 根据狄克逊和韦利的理论对结果进行解释，表明该酶本身存在三个可电离基团，酶-底物复合物存在一个可电离基团。4. 根据反应物的电离状态以及竞争性抑制剂的抑制结果，提出了粟酒裂殖酵母酸性磷酸酶催化磷酸单酯水解的模型。