http://scholars.ntou.edu.tw/handle/123456789/22126
標題: | Altering the substrate specificity of recombinant L-rhamnose isomerase from Thermoanaerobacterium saccharolyticum NTOU1 to favor D-allose production | 作者: | Wen-Chi Tseng Yu-Chun Chen Hao-Chin Chang Chia-Jui Lin Tsuei-Yun Fang |
關鍵字: | L-rhamnose isomerase;D-allose;D-allulose;Thermoanaerobacterium saccharolyticum;mutagenesis | 公開日期: | 27-八月-2022 | 出版社: | Elsevier | 卷: | 358 | 起(迄)頁: | 9-16 | 來源出版物: | Journal of Biotechnology | 摘要: | L-Rhamnose isomerase (L-RhI) catalyzes rare sugar isomerization between aldoses and ketoses. In an attempt to alter the substrate specificity of Thermoanaerobacterium saccharolyticus NTOU1 L-RhI (TsRhI), residue Ile102 was changed to other polar or charged amino acid residues by site-directed mutagenesis. The results of activity-screening using different substrates indicate that I102N, I102Q, and I102R TsRhIs can increase the preference against D-allose in comparison with the wild-type enzyme. The catalytic efficiencies of the purified I102N, I102Q, and I102R TsRhIs against D-allose are 148 %, 277 %, and 191 %, respectively, of that of wild-type enzyme, while those against L-rhamnose are 100 %, 167 % and 87 %, respectively. Mutant I102N, I102Q, and I102R TsRhIs were noted to have the altered substrate specificity, and I102Q TsRhI has the highest catalytic efficiency against D-allose presumably through the formation of an additional hydrogen bond with D-allose. The purified wild-type and mutant TsRhIs were further used to produce D-allose from 100 g/L D-fructose in the presence of D-allulose 3-epimerase, and the yields can reach as high as 22 % D-allulose and 12 % D-allose upon equilibrium. I102Q TsRhI takes only around half of the time to reach the same 12 % D-allose yield, suggesting that this mutant enzyme has a potential to be applied in D-allose production. |
URI: | http://scholars.ntou.edu.tw/handle/123456789/22126 | DOI: | 10.1016/j.jbiotec.2022.08.015 |
顯示於: | 食品科學系 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。