58993-79-6Relevant articles and documents
Iterative Alanine Scanning Mutagenesis Confers Aromatic Ketone Specificity and Activity of L-Amine Dehydrogenases
Mu, Xiaoqing,Wu, Tao,Mao, Yong,Zhao, Yilei,Xu, Yan,Nie, Yao
, p. 5243 - 5253 (2021/11/16)
Direct reductive amination of prochiral ketones catalyzed by amine dehydrogenases is attractive in the synthesis of active pharmaceutical ingredients. Here, we report the protein engineering of L-Bacillus cereus amine dehydrogenase to allow reactivity on synthetically useful aromatic ketone substrates using an iterative, multiple-site alanine scanning mutagenesis approach. Mutagenesis libraries based on molecular docking, iterative alanine scanning, and double-proximity filter approach significantly expand the scope of active pharmaceutical ingredients relevant building blocks. The eventual quintuple mutant (A115G/T136A/L42A/V296A/V293A) showed reactivity toward aromatic ketones 12 a (5-phenyl-pentan-2-one) and 13 a (6-phenyl-hexan-2-one), which have not been reported to serve as targets of reductive amination by currently available amine dehydrogenases. Docking simulation and tunnel analysis provided valuable insights into the source of the acquired specificity and activity.
Development of an engineered thermostable amine dehydrogenase for the synthesis of structurally diverse chiral amines
Chen, Fei-Fei,Chen, Qi,Liu, Lei,Wang, Dong-Hao,Wang, Zhi-Long,Xu, Jian-He,Zhang, Zhi-Jun,Zheng, Gao-Wei
, p. 2353 - 2358 (2020/05/13)
Amine dehydrogenases (AmDHs) are emerging as a class of attractive biocatalysts for synthesizing chiral amines via asymmetric reductive amination of ketones with inexpensive ammonia as an amino donor. However, the AmDHs developed to date exhibit limited substrate scope. Here, using directed evolution, we engineered a GkAmDH based on a thermostable phenylalanine dehydrogenase from Geobacillus kaustophilus. The newly developed AmDH is able to catalyze reductive amination of a diverse set of ketones and functionalized hydroxy ketones with ammonia or primary amines with up to >99% conversion, thus accessing structurally diverse chiral primary and secondary amines and chiral vicinal amino alcohols, with excellent enantioselectivity (up to >99% ee) and releasing water as the sole by-product.
Upgraded Bioelectrocatalytic N2 Fixation: From N2 to Chiral Amine Intermediates
Chen, Hui,Cai, Rong,Patel, Janki,Dong, Fangyuan,Chen, Hsiaonung,Minteer, Shelley D.
, p. 4963 - 4971 (2019/03/26)
Enantiomerically pure chiral amines are of increasing value in the preparation of bioactive compounds, pharmaceuticals, and agrochemicals. ω-Transaminase (ω-TA) is an ideal catalyst for asymmetric amination because of its excellent enantioselectivity and wide substrate scope. To shift the equilibrium of reactions catalyzed by ω-TA to the side of the amine product, an upgraded N2 fixation system based on bioelectrocatalysis was developed to realize the conversion from N2 to chiral amine intermediates. The produced NH3 was in situ reacted with l-alanine dehydrogenase to generate alanine with NADH as a coenzyme. ω-TA transferred the amino group from alanine to ketone substrates and finally produced the desired chiral amine intermediates. The cathode of the upgraded N2 fixation system supplied enough reducing power to synchronously realize the regeneration of reduced methyl viologen (MV?+) and NADH for the nitrogenase and l-alanine dehydrogenase. The coproduct, pyruvate, was consumed by l-alanine dehydrogenase to regenerate alanine and push the equilibrium to the side of amine. After 10 h of reaction, the concentration of 1-methyl-3-phenylpropylamine achieved 0.54 mM with the 27.6% highest faradaic efficiency and >99% enantiomeric excess (eep). Because of the wide substrate scope and excellent enantioselectivity of ω-TA, the upgraded N2 fixation system has great potential to produce a variety of chiral amine intermediates for pharmaceuticals and other applications.
