Discovery of Two Native Baeyer-Villiger Monooxygenases for Asymmetric Synthesis of Bulky Chiral Sulfoxides

作者：Yan Zhang, Feng Liu, Na Xu, Yinqi Wu, Yu‐Cong Zheng, Qian Zhao, Guo‐Qiang Lin, Hui‐Lei Yu, Jian‐He Xu · 发表于：Applied and Environmental Microbiology · 年份：2018 · DOI：10.1128/aem.00638-18 · 被引用次数：36 · 研究领域：Enzyme Catalysis and Immobilization、Metalloenzymes and iron-sulfur proteins、Chemical Synthesis and Reactions

ABSTRACT Two Baeyer-Villiger monooxygenases (BVMOs), designated Bo BVMO and Am BVMO, were discovered from Bradyrhizobium oligotrophicum and Aeromicrobium marinum , respectively. Both monooxygenases displayed novel features for catalyzing the asymmetric sulfoxidation of bulky and pharmaceutically relevant thioethers. Evolutionary relationship and sequence analysis revealed that the two BVMOs belong to the family of typical type I BVMOs and the subtype ethionamide monooxygenase. Both BVMOs are active toward medium- and long-chain aliphatic ketones as well as various thioether substrates but are ineffective toward cyclohexanone, aromatic ketones, and other typical BVMO substrates. Bo BVMO and Am BVMO showed the highest activities (0.117 and 0.025 U/mg protein, respectively) toward thioanisole among the tested substrates. Furthermore, these BVMOs exhibited distinct activity and excellent stereoselectivity toward bulky and prochiral prazole thioethers, which is a unique feature of this family of BVMOs. No native enzyme has been reported for the asymmetric sulfoxidation of bulky prazole thioethers into chiral sulfoxides. The identification of Bo BVMO and Am BVMO provides an important scaffold for discovering enzymes capable of asymmetrically oxidizing bulky thioether substrates by genome mining. IMPORTANCE Baeyer-Villiger monooxygenases (BVMOs) are valuable enzyme catalysts that are an alternative to the chemical Baeyer-Villiger oxidation reaction. Although BVMOs display broad subs...