文献类型：期刊文献

英文题名：In Silico Rational Design and Protein Engineering of Disulfide Bridges of an α-Amylase from Geobacillus sp. to Improve Thermostability

作者：Zhang, Heng[1];Zhai, Wenxin[1];Lin, Lin[2,3];Wang, Ping[4];Xu, Xiangyang[5];Wei, Wei[1];Wei, Dongzhi[1]

机构：[1]East China Univ Sci & Technol, Newworld Inst Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Shanghai Univ Med & Hlth Sci, Shanghai 200093, Peoples R China;[3]Natl Engn Res Ctr Nanotechnol, Res Lab Funct Nanomat, Shanghai 200241, Peoples R China;[4]Weigao Shanghai R&D Ctr, Shanghai 201203, Peoples R China;[5]Zaozhuang Jie Nuo Enzyme Co Ltd, Zaozhuang 277100, Peoples R China

年份：2021

卷号：73

期号：9-10

外文期刊名：STARCH-STARKE

收录：;EI(收录号：20212110377745);WOS:【SCI-EXPANDED(收录号:WOS:000651008100001)】；

基金：This research was financially supported by the National Natural Science Foundation of China (No. C31570795), the Shanghai outstanding technical leaders plan (Grant No. 19XD1431900), the National Natural Science Foundation of China (Grant Nos. 81830052, 81530053) and Shanghai Key Laboratory of Molecular Imaging (18DZ2260400).

语种：英文

外文关键词：α ‐ amylase; disulfide bonds; Geobacillus stearothermophilus; immobilized; thermostability

摘要：A thermostable alpha-amylase gene (AmySN) from Geobacillus stearothermophilus DMSZ 456 with an open reading frame of 1446 bp, encoding 481 amino acids is cloned. The optimal pH and temperature of AmySN are 6.0 and 75 degrees C. Through site-directed mutation, the optimum temperature of the mutant AmyS2 (A27C-A90C) is increased from 75 to 80 degrees C and shows enhanced T-1/2 of 104.9 min at 90 degrees C in comparison to the wild type (52.9 min). The mutant AmyS2 is immobilized on epoxy-functionalized supports to obtain immobilized enzyme: I-AmyS2. Additionally, I-AmyS2 shows an enhanced T-1/2 (204.9 min at 90 degrees C), compared with free enzyme AmyS2 (104.9 min). Enzyme activity could remain above 90% after 6 reactions. In maize starch saccharification (100 degrees C), AmyS2 shows better starch hydrolytic efficiency. The final concentration of reducing sugar is 25.9 mg mL(-1), which is higher than the final concentration of wild-type (22.6 mg mL(-1)), reducing cost and improving efficiency.