文献类型：期刊文献

英文题名：Cloning and Characterization of a Cold-Adapted Endo-1,5-α-L-arabinanase from Paenibacillus polymyxa and Rational Design for Acidic Applicability

作者：Wang, Shaohua[1];Yang, Ying[1];Yang, Rujian[1];Zhang, Jian[1];Chen, Min[1];Matsukawa, Shingo[2];Xie, Jingli[1];Wei, Dongzhi[1]

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Dept Food Sci & Technol, Sch Biotechnol, Shanghai 200237, Peoples R China;[2]Tokyo Univ Marine Sci & Technol, Dept Food Sci & Technol, Tokyo 1088477, Japan

年份：2014

卷号：62

期号：33

起止页码：8460

外文期刊名：JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY

收录：;EI(收录号：20151600748047);WOS:【SCI-EXPANDED(收录号:WOS:000340738700029)】；

基金：This work supported by the National Special Fund for State Key Laboratory of Bioreactor Engineering (2060204), partially supported by the National Natural Science Foundation of China (No. 31201296) and the Fundamental Research Funds for the Central Universities, People's Republic of China.

语种：英文

外文关键词：arabinanase; cold-adapted; site-directed mutagenesis; molecular modeling; pH stability

摘要：AbnZ1, with optimal pH of 6.0 and optimal temperature of 40 degrees C, is a cold-adapted endo-1,5-alpha-L-arabinanase encoded by the gene abnZ1 from Paenibacillus polymyxa Z6. The specific activity of AbnZ1 remained 54.1% of maximum at 5 degrees C. To apply AbnZ1 in acidic conditions, three basic hsitidine (His) residues, His(48), His(218), and His(297), around the catalytic domain were selected as mutation sites, which were replaced with Asp, Glu, Arg, and Lys, respectively, to yield 12 mutants, H48D/E/R/K, H218D/E/R/K, and H297D/E/R/K. The optimum pH of mutant H218D shifted toward the acidic direction by 0.5 unit, and the relative activity was enhanced from 20.4 to 55.796 at pH 5.0. Furthermore, the specific activity of H218D in optimal conditions was 82.6 U/mg versus that of wild type, 73.4 U/mg, and the K-m decreased from 11.9 to 7.1 mg/mL. This work provided an arabinanase candidate for juice clarification and pectin extraction.