光酶催化 z-bio 2025-01-03 467

　　With the support of the National Natural Science Foundation of China projects (approval numbers: 22277053, 22122305, 21927814, 223B2703), the collaborative team of Huang Xiaoqiang from Nanjing University and Wang Binju from Xiamen University has made new progress in the field of photocatalytic catalysis. The related achievements are titled "Synergistic Photobiocatalysis for Enantioselective Triple Radical Sorting" and were published online in the journal Nature on November 22, 2024. The paper link is: https://www.nature.com/articles/s41586-024-08399-5 .

　　Enzymes, as catalysts in nature, play a crucial role in various physiological processes of living systems, and are also indispensable tools in basic research and multiple application fields such as biomanufacturing. Although significant progress has been made in the field of enzyme catalysis in recent years, most of the enzymatic reactions currently studied are limited to single-molecule or bimolecular transformations. To achieve ordered conversion of three different substrates regulated by a single protein, there are still significant challenges. Based on this, the team ingeniously integrated [Ru (bpy) 3] 2+- based photocatalytic and protein directed evolution techniques to "reshape" benzaldehyde lyase into a novel free radical enzyme that catalyzes non natural three component reactions (Figure). The team adopted a semi rational iterative substitution point specific mutation strategy, introducing 5 mutation sites to rapidly reconstruct the enzyme's active pocket, effectively improving the efficiency of non natural reactions, and accurately guiding pre chiral free radical intermediates to complete high stereochemical selectivity bonding processes. The advantage of this system lies in its ability to flexibly combine three variable substrates, breaking through the limitations of natural enzymes that typically catalyze single-molecule or bimolecular transformations, and enriching the possibilities and diversity of photo biosynthesis. The team conducted in-depth exploration of the reaction mechanism of the system through various methods such as enzymatic experiments, photochemical experiments, electron paramagnetic resonance spectroscopy research, and theoretical calculations, providing ideas for the development of new catalytic modes in the future.