Xingyi Zhang, Yinghui Feng, Yuanzhe Hua, Chuanxi Zhang, Bohuan Fang, Xiang Long, Yue Pan, Bei Gao, John Z H Zhang, Lijun Li, Hui Ni, Lujia Zhang
{"title":"Biosynthesis of eriodictyol in citrus waster by endowing P450BM3 activity of naringenin hydroxylation.","authors":"Xingyi Zhang, Yinghui Feng, Yuanzhe Hua, Chuanxi Zhang, Bohuan Fang, Xiang Long, Yue Pan, Bei Gao, John Z H Zhang, Lijun Li, Hui Ni, Lujia Zhang","doi":"10.1007/s00253-023-12867-9","DOIUrl":null,"url":null,"abstract":"<p><p>The flavonoid naringenin is abundantly present in pomelo peels, and the unprocessed naringenin in wastes is not friendly for the environment once discarded directly. Fortunately, the hydroxylated product of eriodictyol from naringenin exhibits remarkable antioxidant and anticancer properties. The P450s was suggested promising for the bioconversion of the flavonoids, but less naturally existed P450s show hydroxylation activity to C3' of the naringenin. By well analyzing the catalytic mechanism and the conformations of the naringenin in P450, we proposed that the intermediate Cmpd I ((porphyrin)Fe = O) is more reasonable as key conformation for the hydrolyzation, and the distance between C3'/C5' of naringenin to the O atom of CmpdI determines the hydroxylating activity for the naringenin. Thus, the \"flying kite model\" that gradually drags the C-H bond of the substrate to the O atom of CmpdI was put forward for rational design. With ab initio design, we successfully endowed the self-sufficient P450-BM3 hydroxylic activity to naringenin and obtained mutant M5-5, with k<sub>cat</sub>, K<sub>m</sub>, and k<sub>cat</sub>/K<sub>m</sub> values of 230.45 min<sup>-1</sup>, 310.48 µM, and 0.742 min<sup>-1</sup> µM<sup>-1</sup>, respectively. Furthermore, the mutant M4186 was screened with k<sub>cat</sub>/K<sub>m</sub> of 4.28-fold highly improved than the reported M13. The M4186 also exhibited 62.57% yield of eriodictyol, more suitable for the industrial application. This study provided a theoretical guide for the rational design of P450s to the nonnative compounds. KEY POINTS: •The compound I is proposed as the starting point for the rational design of the P450BM3 •\"Flying kite model\" is proposed based on the distance between O of Cmpd I and C3'/C5' of naringenin •Mutant M15-5 with 1.6-fold of activity than M13 was obtained by ab initio modification.</p>","PeriodicalId":8342,"journal":{"name":"Applied Microbiology and Biotechnology","volume":null,"pages":null},"PeriodicalIF":3.9000,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Microbiology and Biotechnology","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1007/s00253-023-12867-9","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/1/8 0:00:00","PubModel":"Epub","JCR":"Q2","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The flavonoid naringenin is abundantly present in pomelo peels, and the unprocessed naringenin in wastes is not friendly for the environment once discarded directly. Fortunately, the hydroxylated product of eriodictyol from naringenin exhibits remarkable antioxidant and anticancer properties. The P450s was suggested promising for the bioconversion of the flavonoids, but less naturally existed P450s show hydroxylation activity to C3' of the naringenin. By well analyzing the catalytic mechanism and the conformations of the naringenin in P450, we proposed that the intermediate Cmpd I ((porphyrin)Fe = O) is more reasonable as key conformation for the hydrolyzation, and the distance between C3'/C5' of naringenin to the O atom of CmpdI determines the hydroxylating activity for the naringenin. Thus, the "flying kite model" that gradually drags the C-H bond of the substrate to the O atom of CmpdI was put forward for rational design. With ab initio design, we successfully endowed the self-sufficient P450-BM3 hydroxylic activity to naringenin and obtained mutant M5-5, with kcat, Km, and kcat/Km values of 230.45 min-1, 310.48 µM, and 0.742 min-1 µM-1, respectively. Furthermore, the mutant M4186 was screened with kcat/Km of 4.28-fold highly improved than the reported M13. The M4186 also exhibited 62.57% yield of eriodictyol, more suitable for the industrial application. This study provided a theoretical guide for the rational design of P450s to the nonnative compounds. KEY POINTS: •The compound I is proposed as the starting point for the rational design of the P450BM3 •"Flying kite model" is proposed based on the distance between O of Cmpd I and C3'/C5' of naringenin •Mutant M15-5 with 1.6-fold of activity than M13 was obtained by ab initio modification.
期刊介绍:
Applied Microbiology and Biotechnology focusses on prokaryotic or eukaryotic cells, relevant enzymes and proteins; applied genetics and molecular biotechnology; genomics and proteomics; applied microbial and cell physiology; environmental biotechnology; process and products and more. The journal welcomes full-length papers and mini-reviews of new and emerging products, processes and technologies.