Engineering a Trypsin-Resistant Thermophilic alpha-Galactosidase to Enhance Pepsin Resistance, Acidic Tolerance, Catalytic Performance, and Potential in the Food and Feed Industry

文献类型： 外文期刊

第一作者： Niu, Canfang

作者： Niu, Canfang;Wan, Xiangyuan;Niu, Canfang

作者机构：

关键词： alpha-galactosidases; pepsin resistance; trypsin resistance; stability at low pH; thermostability; catalytic performance; hydrolysis of soybean galactosaccharides; loop replacement; residue substitution in proximity to pepsin cleavage site

期刊名称：JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY （ 影响因子：5.279； 五年影响因子：5.269 ）

ISSN： 0021-8561

年卷期： 2020 年 68 卷 39 期

页码：

收录情况： SCI

摘要： alpha-Galactosidase has potential applications, and attempts to improve proteolytic resistance of enzymes have important values. We use a novel strategy for genetic manipulation of a pepsin-sensitive region specific for a pepsin-sensitive but trypsin-resistant high-temperature-active Gal27B from Neosartorya fischeri to screen mutants with enhanced pepsin resistance. All enzymes were produced in Pichia pastoris to identify the roles of loop 4 (Gal27B-A23) and its key residue at position 156 (Gly156Arg/Pro/His) in pepsin resistance. Gal27B-A23 and Gly156Arg/Pro/His elevated pepsin resistance, thermostability, stability at low pH, activity toward raffinose (5.3-6.9-fold) and stachyose (about 1.3-fold), and catalytic efficiencies (up to 4.9-fold). Replacing the pepsin cleavage site Glu155 with Gly improved pepsin resistance but had no effect on pepsin resistance when Arg/Pro/His was at position 156. Thus, pepsin resistance could appear to occur through steric hindrance between the residue at the altered site and neighboring pepsin active site. In the presence of pepsin or trypsin, all mutations increased the ability of Gal27B to hydrolyze galactosaccharides in soybean flour (up to 9.6- and 4.3-fold, respectively) and promoted apparent metabolizable energy and nutrient digestibility in soybean meal for broilers (1.3-1.8-fold). The high activity and tolerance to heat, low pH, and protease benefit food and feed industry in a cost-effective way.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序