Theaflavins (TFs) are good for health because of their bioactivities. Enzymatic synthesis of TFs has garnered much attention; however, the source and activity of the enzymes needed limit their wide application. In this study, a microbial polyphenol oxidase from was screened for the synthesis of theaflavin-3,3'-digallate (TFDG). Based on structural and mechanistic analyses of the enzyme, the O-O bond dissociation was identified as the rate-determining step. To address this issue, a transition state (TS) conformation optimization strategy was adopted to stabilize the spatial conformation of the O-O bond dissociation, which improved the catalytic efficiency of tyrosinase. Under the optimum transformation conditions of pH 4.0, temperature 25 °C, (-)-epigallocatechin gallate/epicatechin gallate molar ratio of 2:1, and time of 30 min, Mu (Tyr) produced 960.36 mg/L TFDG with a 44.22% conversion rate, which was 6.35-fold higher than that of the wild type. Thus, the method established has great potential in the synthesis of TFDG and other TFs.
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| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10179947 | PMC |
| http://dx.doi.org/10.3390/molecules28093831 | DOI Listing |
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