Directed Evolution of the UDP-Glycosyltransferase UGT_BL1 for Highly Regioselective and Efficient Biosynthesis of Natural Phenolic Glycosides

The O-glycosylation of polyphenols for the synthesis of glycosides has garnered substantial attention in food research applications. However, the practical utility of UDP-glycosyltransferases (UGTs) is significantly hindered by their low catalytic efficiency and suboptimal regioselectivity. The concurrent optimization of the regioselectivity and activity during the glycosylation of polyphenols presents a formidable challenge. Here, we addressed the long-standing activity–regioselectivity tradeoff in glycosyltransferase UGTBL1 through systematic enzyme engineering. The optimal combination of mutants, N61S/I62M/D63W/A208R/P218W/R282W (SMWRW1W2), yielded a 6.1-fold improvement in relative activity and a 17.3-fold increase in the ratio of gastrodin to para-hydroxybenzyl alcohol-4′-O-β-glucoside (with 89.5% regioselectivity for gastrodin) compared to those of the wild-type enzyme and ultimately allowed gram-scale production of gastrodin (1,066.2 mg/L) using whole-cell biocatalysis. In addition, variant SMWRW1W2 exhibited a preference for producing phenolic glycosides from several substrates. This study lays the foundation for the engineering of additional UGTs and the practical applications of UGTs in regioselective retrofitting

CuS/Co-Ferrocene-MOF Nanocomposites for Photothermally Enhanced Chemodynamic Antibacterial Therapy

Infections caused by bacteria pose a serious threat to public health, and there is a need for numerous innovative, antibiotic-free antimicrobial medicines. Herein, we describe the synthesis of CuS/Co-ferrocene-MOF (CuS/Co-Fc-MOF) nanocomposites, formed by coupling CuS nanoparticles (NPs) to two-dimensional (2D) Co-Fc-MOF nanosheets, that constitutes an antimicrobial platform capable of near-infrared (NIR) photothermal promotion of chemodynamic antibacterial. 2D CuS/Co-Fc-MOF nanocomposites consist of Co-Fc-MOF nanosheets with dimensions of approximately 100–200 nm and thicknesses of 13.1–15.6 nm, where CuS NPs, with a size of about 8 nm, are excellently dispersed on the surface of Co-Fc-MOF nanosheets. The diverse valence states of cobalt and iron in the CuS/Co-Fc-MOF nanosheets enable them to undergo Fenton-like reactions with H2O2, thus generating highly oxidizing ·OH for chemodynamic therapy (CDT). The utilization of the local surface plasmonic resonance effect of CuS NPs enables the enhancement of CDT activity in CuS/Co-Fc-MOF nanosheets under near-infrared (NIR) laser irradiation. More importantly, CuS/Co-Fc-MOF nanosheets can achieve rapid (15 min) NIR laser-assisted killing of both S. aureus and E. coli in a bacterial infection microenvironment compared to Co-Fc-MOF nanosheets. Therefore, the CuS/Co-Fc-MOF nanosheets can be employed as a promising nanoagent to promote photothermally augmented chemodynamic antibacterial therapy