Ford C
Food Science and Human Nutrition Department, 2312 Food Sciences Building, Iowa State University, Ames, IA 50011, USA.
Curr Opin Biotechnol. 1999 Aug;10(4):353-7. doi: 10.1016/S0958-1669(99)80064-0.
The potential operating temperature of Aspergillus awamori glucoamylase has been increased by several thermostable mutations that reduce irreversible thermoinactivation. Other mutations have been isolated that increase selectivity of alpha-1,4 over alpha-1,6 glycosidic bonds, resulting in fewer alpha-1,6 linked reversion products, thus increasing glucose yield. Interestingly, many thermostable mutations also increase selectivity and yields, suggesting that enzyme flexibility plays a role in accommodating unwanted bulky alpha-1,6 bonds in the active site.
泡盛曲霉葡萄糖淀粉酶的潜在操作温度已通过几种减少不可逆热失活的热稳定突变而提高。还分离出了其他突变，这些突变增加了α-1,4糖苷键相对于α-1,6糖苷键的选择性，减少了α-1,6连接的逆转产物，从而提高了葡萄糖产量。有趣的是，许多热稳定突变也提高了选择性和产量，这表明酶的灵活性在容纳活性位点中不需要的庞大α-1,6键方面发挥了作用。
