Chemogenetic Evolution of Diversified Photoenzymes for Enantioselective [2 + 2] Cycloadditions in Whole Cells.
Guo, J., Qian, J., Cai, D., Huang, J., Yang, X., Sun, N., Zhang, J., Pang, T., Zhao, W., Wu, G., Chen, X., Zhong, F., Wu, Y.(2024) J Am Chem Soc 146: 19030-19041
- PubMed: 38976645 
- DOI: https://doi.org/10.1021/jacs.4c03087
- Primary Citation of Related Structures:  
8ZF1 - PubMed Abstract: 
Artificial photoenzymes with novel catalytic modes not found in nature are in high demand; yet, they also present significant challenges in the field of biocatalysis. In this study, a chemogenetic modification strategy is developed to facilitate the rapid diversification of photoenzymes. This strategy integrates site-specific chemical conjugation of various artificial photosensitizers into natural protein cavities and the iterative mutagenesis in cell lysates. Through rounds of directed evolution, prominent visible-light-activatable photoenzyme variants were developed, featuring a thioxanthone chromophore. They successfully enabled the enantioselective [2 + 2] photocycloaddition of 2-carboxamide indoles, a class of UV-sensitive substrates that are traditionally challenging for known photoenzymes. Furthermore, the versatility of this photoenzyme is demonstrated in enantioselective whole-cell photobiocatalysis, enabling the efficient synthesis of enantioenriched cyclobutane-fused indoline tetracycles. These findings significantly expand the photophysical properties of artificial photoenzymes, a critical factor in enhancing their potential for harnessing excited-state reactivity in stereoselective transformations.
Organizational Affiliation: 
Hubei Key Laboratory of Bioinorganic Chemistry & Materia Medica, Hubei Engineering Research Center for Biomaterials and Medical Protective Materials, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan 430074, China.