91298-66-7Relevant articles and documents
Crystal Structures and Catalytic Mechanism of l-erythro-3,5-Diaminohexanoate Dehydrogenase and Rational Engineering for Asymmetric Synthesis of β-Amino Acids
Chen, Xi,Feng, Jinhui,Li, Jian,Li, Jianjiong,Liu, Na,Liu, Weidong,Sheng, Xiang,Wu, Lian,Wu, Qiaqing,Zhou, Jiahai,Zhu, Dunming
supporting information, p. 10203 - 10210 (2021/03/26)
Amino acid dehydrogenases (AADHs) have shown considerable potential as biocatalysts in the asymmetric synthesis of chiral amino acids. However, compared to the widely studied α-AADHs, limited knowledge is available about β-AADHs that enable the synthesis of β-amino acids. Herein, we report the crystal structures of a l-erythro-3,5-diaminohexanoate dehydrogenase and its variants, the only known member of β-AADH family. Crystal structure analysis, site-directed mutagenesis studies and quantum chemical calculations revealed the differences in the substrate binding and catalytic mechanism from α-AADHs. A number of rationally engineered variants were then obtained with improved activity (by 110–800 times) toward various aliphatic β-amino acids without an enantioselectivity trade-off. Two β-amino acids were prepared by using the outstanding variants with excellent enantioselectivity (>99 % ee) and high isolated yields (86–87 %). These results provide important insights into the molecular mechanism of 3,5-DAHDH, and establish a solid foundation for further design of β-AADHs for the asymmetric synthesis of β-amino acids.
Improving Catalytic Activity and Reversing Enantio-Specificity of ω-Transaminase by Semi-Rational Engineering en Route to Chiral Bulky β-Amino Esters
Wang, Yingang,Feng, Jinhui,Dong, Wenyue,Chen, Xi,Yao, Peiyuan,Wu, Qiaqing,Zhu, Dunming
, p. 3396 - 3400 (2021/06/21)
The application of wild-type ω-transaminase was limited by steric hindrance towards bulky substrates, therefore improvement of the catalytic efficiency and stereoselectivity toward substrates with two bulky substituent adjacent to the carbonyl is of general interest. In this study, according to the double substrate binding pocket theory, a (S)-selective ω-transaminase from the Burkholderia vietnamiensis G4, which showed puny catalytic activity toward the β-keto esters with small steric hindrance, was engineered to accept bulky β-keto esters, which were not accessible by any wild-type enzyme. A few desired variants were obtained that exhibited activity toward bulky β-keto esters. Furthermore, a substrate-dependent shift in enantio-preference of HBV variant towards β-keto esters with linear or branched aliphatic substituents was observed. The best variant was applied to the asymmetric synthesis of aliphatic β-amino acids at semi-preparative scale with high yield and enantioselectivity. This study will improve the general understanding and inspire further engineering work for reversing enantio-specificity of ω-transaminases.
Enantioselektive Synthese von β-Aminosaeuren - TMS-SAMP als chirales Ammoniak-Aequivalent in der azaanalogen Michael-Addition an α,β-ungesaettigte Ester
Enders, Dieter,Wahl, Heiner,Bettray, Wolfgang
, p. 527 - 529 (2007/10/02)
Stichworte: Aminosaeuren * Asymmetrische Synthesen * Chirale Hilfsstoffe * Michael-Additionen
