Braun H
Biochim Biophys Acta. 1976 Dec 8;452(2):452-7. doi: 10.1016/0005-2744(76)90195-9.
Conduritol-B-epoxide, a compound structurally related to the substrates of external yeast beta-fructosidase (beta-D-fructofuranoside fructohydrolase, EC 3.2.1.26), is an active-site directed inhibitor of this enzyme. The inactivation is irreversible and first-order with respect to time and inhibitor concentration. From the kinetic data obtained, it is concluded that one molecule of inhibitor reacts with one molecule of the enzyme causing inactivation. The inactivation is prevented by the presence of substrates. The pH-dependence of inactivation shows two dissociating groups in the enzyme with pKa values 3.05 and 6.8 being involved in the inactivation process. A carboxylate at the active site with pKa 3.05 is suggested to be the reactive group with conduritol-B-epoxide.
伴多醇 - B - 环氧化物是一种在结构上与外源性酵母β - 果糖苷酶（β - D - 呋喃果糖苷果糖水解酶，EC 3.2.1.26）的底物相关的化合物，是该酶的活性位点导向抑制剂。失活是不可逆的，且在时间和抑制剂浓度方面呈一级反应。从获得的动力学数据可以得出结论，一分子抑制剂与一分子酶反应导致失活。底物的存在可防止失活。失活的pH依赖性表明酶中有两个解离基团参与失活过程，其pKa值分别为3.05和6.8。活性位点上pKa为3.05的羧酸盐被认为是与伴多醇 - B - 环氧化物反应的基团。
