环糊精葡萄糖基转移酶的分子改造及其在合成α-熊果苷中的应用

Molecular modification of cyclodextrin glucosyltransferase and its application in the synthesis of α-arbutin

摘要:

α-熊果苷在化妆品和医药领域具有重要应用价值，但从植物组织中提取产率低，极大地限制了其应用。本研究利用戈特沙尔克厌氧分支杆菌(Anaerobranca gottschalkii)来源的环糊精葡萄糖基转移酶(cyclodextrin glucosyltransferase, CGTase)，以麦芽糊精为供体，对苯二酚为受体，催化合成α-熊果苷。通过定点饱和突变和定点突变筛选到突变体AgCGTase-F235G-N166H，活力是野生型的3.48倍。通过优化反应pH、温度、对苯二酚添加量，转化率在最优反应条件下达到63%。综上所述，本研究成功构建了一株能高效合成α-熊果苷并具有较高苯二酚转化率的菌株，对于降低α-熊果苷工业化的生产成本，提高产物的转化率方面具有重要的应用潜力。

Abstract:

α-arbutin has important applications in cosmetics and medicine. However, the extraction yield from plant tissues is relatively low, which restricts its application value. In this study, we investigated the synthesis of α-arbutin using maltodextrin as the donor and hydroquinone as the acceptor, using a cyclodextrin glucosyltransferase (CGTase) from Anaerobranca gottschalkii. We performed site-saturated and site-directed mutagenesis on AgCGTase. The activity of the variant AgCGTase-F235G-N166H was 3.48 times higher than that of the wild type. Moreover, we achieved a conversion rate of 63% by optimizing the reaction pH, temperature, and hydroquinone addition amount. Overall, this study successfully constructed a strain with improved conversion rate for the synthetic production of α-arbutin and hydroquinone. These findings have significant implications for reducing the industrial production cost of α-arbutin and enhancing the conversion rate of the product.