α-转移葡萄糖苷酶的转苷作用机理探究

Exploration into the enzymatic mechanism of α-transglucosidase

通过用高效液相色谱(HPLC)全程跟踪转苷反应过程的方法,对α-转移葡萄糖苷酶将麦芽糖转变为异麦芽糖的酶促反应作用机理进行了探讨。结果表明,在转化过程中α-转移葡萄糖苷酶先把麦芽糖的α-1,4糖苷键打断,分解为两个葡萄糖单元,然后再通过α-1,6糖苷键连接的方式重新键合,完成从麦芽糖到异麦芽糖的异构化过程。而由麦芽糖生成异麦芽糖的整个转苷过程是在分子内进行的。与此同时,由麦芽糖分解出来的部分葡萄糖单元通过分子间作用的方式与麦芽糖或异麦芽糖发生反应,生成潘糖或者异麦芽三糖。

Using High Performance Liquid Chromatography（HPLC）to track the transfer-glycoside process all the way.The enzymatic mechanism of α-glucosidase transferring maltose into isomaltose has been discussed.The results showed that in the transformation process,the α-glucosidase cut the α-1,4 glycosidic bonds into two glucose units firstly,then re-bonded by α-1,6 glycosidic linkage.And the isomerization process from maltose to isomaltose finished.The transglycosidation was happened intramolecularly.At the same time,the glucose units which dissociated from maltose reacted intermolecularly with maltose or isomaltose to generate panose or isomaltotriose.