华中科技大学吴钰周团队团队报道了全细胞中对映选择性[2+2]环加成的多种光酶的化学遗传学进化。相关研究成果发表在2024年7月8日出版的《美国化学会志》。

具有自然界中未发现的新型催化模式的人工光酶需求量很大，然而，它们也在生物催化领域提出了重大挑战。

该文中，研究人员开发了一种化学遗传修饰策略，以促进光酶的快速多样化。该策略将各种人工光敏剂的位点特异性化学偶联整合到天然蛋白质腔中，并在细胞裂解物中进行迭代诱变。通过一轮又一轮的定向进化，开发出了突出的可见光可激活的具有硫黄酮发色团的光酶变体。

他们成功地实现了2-羧酰胺吲哚的对映选择性[2+2]光环加成，这是一类紫外线敏感底物，传统上对已知的光酶具有挑战性。此外，这种光酶的多功能性在对映选择性全细胞光生物催化中得到了证明，从而能够有效合成对映富集的环丁烷稠合吲哚啉四环。

这些发现显著扩展了人工光酶的光物理性质，是增强其在立体选择性转化中利用激发态反应性潜力的关键因素。

附：英文原文

Title: Chemogenetic Evolution of Diversified Photoenzymes for Enantioselective [2 + 2] Cycloadditions in Whole Cells

Author: Juan Guo, Junyi Qian, Daihong Cai, Jianjian Huang, Xinjie Yang, Ningning Sun, Junshuai Zhang, Tengfei Pang, Weining Zhao, Guojiao Wu, Xi Chen, Fangrui Zhong, Yuzhou Wu

Issue&Volume: July 8, 2024

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.

DOI: 10.1021/jacs.4c03087

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c03087