کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6488069 | 1416354 | 2018 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Improvement of enzymatic properties of Rhizopus oryzae α-amylase by site-saturation mutagenesis of histidine 286
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Optimal pH and ideal functioning temperature for fungal α-amylase can greatly contribute to improving enzyme efficiency in maltose-forming ability. This work aimed to improve the enzymatic properties of Rhizopus oryzae α-amylase by site-saturation mutagenesis of histidine 286. The biochemical properties of selected mutant enzymes were modified to increase their enzymatic efficiencies compared to their wild-type counterparts. For instance, the optimum temperature of mutants H286â¯L, H286I, H286S and H286â¯T was increased from 50â¯Â°C to 55â¯Â°C, while a similar increase was observed for H286â¯P from 50â¯Â°C to 60â¯Â°C. The optimum pH of mutants H286â¯L, H286I and H286D shifted from 5.5 to 5.0, and the optimum pH of mutant H286E shifted from 5.5 to 4.5. The results obtained showed that the mutant H286I showed a 1.5-fold increase in half-life at 55â¯Â°C and the mutant H286E showed a 6.43-fold increase in half-life at a pH of 4.5. Furthermore, the ability to form maltose from soluble starch for mutants H286â¯L and H286â¯M was significantly improved under the optimum conditions determined in the study. The catalytic mechanism responsible for improved maltose-forming ability was confirmed through molecular docking simulations with maltotriose among wild-type and mutant enzymes. The mutants with improved enzymatic properties that were attained in this work may help in future computer-aided directed evolution of fungal α-amylase.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Enzyme and Microbial Technology - Volume 117, October 2018, Pages 96-102
Journal: Enzyme and Microbial Technology - Volume 117, October 2018, Pages 96-102
نویسندگان
Song Li, Qian Yang, Bin Tang, Ana Chen,