中国农业科技导报2018，Vol.20Issue(5)：26-33,8.DOI:10.13304/j.nykjdb.2017.0350
来源于脂环酸芽孢杆菌的GH1家族β-葡萄糖苷酶的葡萄糖耐受性分子改造
Glucose-Tolerance Molecular Modification of GH1 β-glucosidase from Alicyclobacillus sp. A4
摘要
Abstract
Soybean isoflavones has the effect of promoting growth and accelerating protein synthesis, but it mainly exists in the soybean meal with inactive and bounded form. In the feed field based on corn and soybean meal, β-glucosidase could convert the bounded soybean isoflavones into the free and active aglycone, but the transformation process was inhibited by the relatively high concentration of glucose in the intestinal tract. Compared with the GH3 family, β-glucosidase from GH1 family has not only higher glucose tolerance, but also can be stimulated by glucose with a certain range of concentration. Hence, it shows great potential for application in the field of feed. This study cloned and expressed a GH1 family β-glucosidase AsBG1 from Alicyclobacillus sp. A4 with high glucose tolerance (IC50800 mmol/L).In order to further improve the glucose tolerance of AsBG1, the molecular mutation of AsBG1 was conducted focusing on the non-active binding sites of glucose in catalytic channel and based on homology modeling, sequence alignment and molecular docking.The glucose tolerance test showed that with 5 mmol/L pNPG as substrate, the specific activity of WT, H315R and M325K was stimulated to 125％, 163％ and 162％ by 100 mmol/L glucose, respectively. And the IC50of H315R increased to 1 200 mmol/L. With 1 mmol/L daidzin as substrate, the activity of WT, H315R and M325K was stimulated to 163％, 212％ and 226％ by 10 mmol/L glucose, respectively. This study enriched the understanding of glucose tolerance mechanism of GH1 family and had important guiding significance for the relevant molecular modification of tolerance in the future.关键词
β-葡萄糖苷酶/葡萄糖耐受性/分子改造/大豆异黄酮Key words
β-glucosidase/glucose tolerance/molecular modification/soybean isoflavone分类
生物科学引用本文复制引用
曹慧方,李新新,张玥琦,石鹏君,柏映国,姚斌..来源于脂环酸芽孢杆菌的GH1家族β-葡萄糖苷酶的葡萄糖耐受性分子改造[J].中国农业科技导报,2018,20(5):26-33,8.基金项目
中国农业科学院科技创新工程协同创新任务(CAAS-XTCX2016011-01)资助. （CAAS-XTCX2016011-01）
