Lowe G, Potter B V
Biochem J. 1981 Oct 1;199(1):227-33. doi: 10.1042/bj1990227.
Adenosine 5'[gamma(S)-16O, 17O, 18O]triphosphate has been synthesized and used to determine the stereochemical course of phosphoryl transfer catalysed by yeast hexokinase. The chirality at phosphorus of the D-glucose 6-[16O,17O,18O]phosphate formed was analysed, after cyclization and methylation, by 31P n.m.r. spectroscopy. The phosphoryl transfer was found to occur with inversion of configuration, with a stereoselectivity in excess of 94%. The simplest interpretation of this result is that the phosphoryl group is transferred between substrates in the enzyme-substrate ternary complex by an 'in line' mechanism.
5'-[γ(S)-16O, 17O, 18O]三磷酸腺苷已被合成,并用于确定酵母己糖激酶催化的磷酰基转移的立体化学过程。在环化和甲基化后,通过31P核磁共振光谱分析了形成的D-葡萄糖6-[16O,17O,18O]磷酸酯磷原子处的手性。发现磷酰基转移以构型翻转的方式发生,立体选择性超过94%。对该结果最简单的解释是,磷酰基通过“直线”机制在酶-底物三元复合物中的底物之间转移。