Chernikevich I P, Makarchikov A F
Institute of Biochemistry, Academy of Sciences of Belarus, Grodno.
Ukr Biokhim Zh (1978). 1998 Jan-Feb;70(1):22-30.
The analysis of the steady-state kinetics of the thiamine triphosphate ester hydrolysis reaction catalyzed by homogeneous thiamine triphosphatase (EC 3.6.1.28; thiamine triphosphate phosphohydrolase) from bovine brain enables us to suggest, that the ThTP binding to the catalytic site of the ThTPase active centre takes place by the phosphate radical. The correct orientation of the substrate molecule occurs by means of the contact of the thiamine component. The crucial role in this process belong to the amino group of the pyrimidine ring and hydrophobic forces. The quaternary nitrogen of thiazole is important for the hydrolytic splitting of the substrate. The hydrolysis of thiamine triphosphate ester occurs through the formation of the ternary enzyme-substrate complex, with the Mg2+ and Mg.ThTP adding being random.
对来自牛脑的均相硫胺三磷酸酶（EC 3.6.1.28；硫胺三磷酸磷酸水解酶）催化的硫胺三磷酸酯水解反应的稳态动力学分析，使我们能够推测，硫胺三磷酸（ThTP）与硫胺三磷酸酶（ThTPase）活性中心的催化位点结合是通过磷酸基团进行的。底物分子的正确取向是通过硫胺成分的接触实现的。在这个过程中，嘧啶环的氨基和疏水力起着关键作用。噻唑的季氮对底物的水解裂解很重要。硫胺三磷酸酯的水解是通过形成三元酶 - 底物复合物发生的，Mg2+和Mg.ThTP的添加是随机的。
