Hu Baodong, Zhao Xinrui, Zhou Jingwen, Li Jianghua, Chen Jian, Du Guocheng
Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.
Science Center for Future Foods, Jiangnan University, Wuxi, Jiangsu, China.
Front Bioeng Biotechnol. 2023 Feb 15;11:1138376. doi: 10.3389/fbioe.2023.1138376. eCollection 2023.
The hydroxylation is an important way to generate the functionalized derivatives of flavonoids. However, the efficient hydroxylation of flavonoids by bacterial P450 enzymes is rarely reported. Here, a bacterial P450 sca-2 whole-cell biocatalyst with an outstanding 3'-hydroxylation activity for the efficient hydroxylation of a variety of flavonoids was first reported. The whole-cell activity of sca-2 was enhanced using a novel combination of flavodoxin Fld and flavodoxin reductase Fpr from In addition, the double mutant of sca-2 (R88A/S96A) exhibited an improved hydroxylation performance for flavonoids through the enzymatic engineering. Moreover, the whole-cell activity of sca-2 (R88A/S96A) was further enhanced by the optimization of whole-cell biocatalytic conditions. Finally, eriodictyol, dihydroquercetin, luteolin, and 7,3',4'-trihydroxyisoflavone, as examples of flavanone, flavanonol, flavone, and isoflavone, were produced by whole-cell biocatalysis using naringenin, dihydrokaempferol, apigenin, and daidzein as the substrates, with the conversion yield of 77%, 66%, 32%, and 75%, respectively. The strategy used in this study provided an effective method for the further hydroxylation of other high value-added compounds.
羟基化是生成黄酮类功能化衍生物的重要途径。然而，细菌P450酶对黄酮类进行高效羟基化的报道很少。在此，首次报道了一种对多种黄酮类具有出色的3'-羟基化活性、用于高效羟基化的细菌P450 sca-2全细胞生物催化剂。通过使用来自[具体来源未提及]的新型黄素氧还蛋白Fld和黄素氧还蛋白还原酶Fpr组合，增强了sca-2的全细胞活性。此外，通过酶工程，sca-2的双突变体（R88A/S96A）对黄酮类表现出改善的羟基化性能。而且，通过优化全细胞生物催化条件，进一步提高了sca-2（R88A/S96A）的全细胞活性。最后，以柚皮素、二氢山奈酚、芹菜素和大豆苷元为底物，通过全细胞生物催化分别制备了黄烷酮、黄烷醇、黄酮和异黄酮的示例产物圣草酚、二氢槲皮素、木犀草素和7,3',4'-三羟基异黄酮，转化率分别为77%、66%、32%和75%。本研究中使用的策略为其他高附加值化合物的进一步羟基化提供了一种有效方法。
