Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
FEBS J. 2012 Sep;279(17):3185-91. doi: 10.1111/j.1742-4658.2012.08698.x. Epub 2012 Aug 2.
Bacteroides thetaiotaomicron VPI-5482 harbors a gene encoding a putative cycloisomaltooligosaccharide glucanotransferase (BT3087) belonging to glycoside hydrolase family 66. The goal of the present study was to characterize the catalytic properties of this enzyme. Therefore, we expressed BT3087 (recombinant endo-dextranase from Bacteroides thetaiotaomicron VPI-5482) in Escherichia coli and determined that recombinant endo-dextranase from Bacteroides thetaiotaomicron VPI-5482 preferentially synthesized isomaltotetraose and isomaltooligosaccharides (degree of polymerization > 4) from dextran. The enzyme also generated large cyclic isomaltooligosaccharides early in the reaction. We conclude that members of the glycoside hydrolase 66 family may be classified into three types: (a) endo-dextranases, (b) dextranases possessing weak cycloisomaltooligosaccharide glucanotransferase activity, and (c) cycloisomaltooligosaccharide glucanotransferases.
拟杆菌属双歧亚种 VPI-5482 携带一个基因，编码一个假定的环糊精寡糖糖基转移酶（BT3087），属于糖苷水解酶家族 66。本研究的目的是表征该酶的催化特性。因此，我们在大肠杆菌中表达了 BT3087（源自拟杆菌属双歧亚种 VPI-5482 的重组内切葡聚糖酶），并确定源自拟杆菌属双歧亚种 VPI-5482 的重组内切葡聚糖酶优先从葡聚糖合成异麦芽糖四糖和异麦芽寡糖（聚合度>4）。该酶还在反应早期产生大的环状异麦芽寡糖。我们得出结论，糖苷水解酶 66 家族的成员可分为三类：（a）内切葡聚糖酶，（b）具有弱环糊精寡糖糖基转移酶活性的葡聚糖酶，和（c）环糊精寡糖糖基转移酶。
