Enzymatic properties of an efficient glucan branching enzyme and its potential application in starch modification
文献类型： 外文期刊
作者： Xia Chengyao 1 ; Yan, Qiao 1 ; Dong Chaonan 1 ; Chen Xiaopei 1 ; Wang Yanxin 1 ; Ding, Li 2 ; Ye Xianfeng 1 ; Jian, Han 3 ;
作者机构： 1.Nanjing Agr Univ, Coll Life Sci, Key Lab Agr Environm Microbiol, Minist Agr, Nanjing 210095, Peoples R China
2.Jiangsu Acad Agr Sci, Inst Vet Immunol Engn, Nanjing, Peoples R China
3.Xinjiang Agr Univ, Coll Agr, Xinjiang 830052, Peoples R China
关键词： Glucan branching enzyme; Aquabacterium sp. strain A7-Y; Potato starch; Retrogradation
期刊名称：PROTEIN EXPRESSION AND PURIFICATION （ 影响因子：1.513； 五年影响因子：1.381 ）
ISSN： 1046-5928
年卷期： 2021 年 178 卷
页码：
收录情况： SCI
摘要： Glucan branching enzymes (GBEs, EC 2.4.1.18) catalyze the formation of a-1,6-linked branch in starch, which is important for the starch modification with prospective properties. In this study, the aqGBE gene encoding an efficient glucan branching enzyme was cloned from Aquabacterium sp. strain A7-Y and successfully expressed in Escherichia coli BL21 (DE3). The specific activity of the purified recombinant enzyme rAqGBE was 2850 U/mg with potato starch as the optimal substrate, and the K-m and V-max values of rAqGBE were 1.18 mg/mL and 588.2 mu mol/min/mg, respectively. Enzymological characterization showed that rAqGBE exhibits its optimal activity under the condition of 40 degrees C and pH 7.0, respectively, which is independent of calcium ions. Otherwise, rAqGBE-treated potato starch showed different chain length distribution compared with control, the numbers of short chains (degree of polymerization, DP < 7) and long chains (DP > 25) increased from 4.5% to 9.6% and 6.1%-15.7% after enzymatic treatment, respectively. In starch anti-ageing assay, with minimum usage of 0.8 mg rAqGBE per g starch, the rAqGBE-treated potato starch exhibited reduced retrogradation properties. Our results indicate that the branching enzyme AqGBE may therefore be a promising tool for the enzymatic modification of starch.
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