943-73-7Relevant articles and documents
Microparticle-based strategy for controlled release of substrate for the biocatalytic preparation of l -homophenylalanine
Zhang, Jielin,Tao, Shanshan,Zhang, Baojie,Wu, Xuri,Chen, Yijun
, p. 1584 - 1587 (2014)
Substrate inhibition is a universal challenge in biocatalytic process development. Herein, a controlled release of substrate from the microparticles was introduced and demonstrated to tackle this issue to increase the biocatalytic efficiency. Using phenylalanine dehydrogenase catalyzed production of l-homophenylalanine as a model reaction, and substrate-loaded microparticles were prepared and used as a reservoir to load a high amount of substrate and to control the release rate into the reaction media. Consequently, highly efficient biocatalysis could be sustainably achieved in the complex reaction system through constantly lowering the substrate concentration.
Investigation of Taniaphos as a chiral selector in chiral extraction of amino acid enantiomers
Xiao, Wenjie,Chen, Shuhuan,Liu, Xiong,Ma, Yu
, p. 292 - 302 (2021/03/29)
Finding chiral selector with high stereoselectivity to a variety of amino acid enantiomers remains a challenge and warrants further research. In this work, Taniaphos, a chiral ligand with rotatable spatial configuration, was employed as a chiral extractant to enantioseparate various amino acid enantiomers. Phenylalanine (Phe), homophenylalanine (Hphe), 4-nitrophenylalanine (Nphe), and 3-chloro-phenylglycine (Cpheg) were used as substrates to evaluate the extraction efficiency. The results revealed that Taniaphos-Cu exhibited good abilities to enantioseparate Phe, Hphe, Nphe, and Cpheg with the highest separation factors (α) of 3.13, 2.10, 2.32, and 2.14, respectively. Taniaphos-Cu is more conducive to combine with D-amino acid in extraction. The influences of pH, Taniaphos-Cu, and concentration and extraction temperature on extraction were comprehensively evaluated. The highest performance factors (pf) for Phe, Hphe, Nphe, and Cpheg at optimal extraction conditions were 0.08892, 0.1250, 0.09621, and 0.08021, respectively. The recognition mechanism between Taniaphos-Cu and amino acid enantiomers was discussed. The coordination interaction between Taniaphos-Cu and -COO?, π-π interaction between Taniaphos-Cu and amino acid enantiomers are important acting forces in chiral extraction. The steric-hindrance between -NH2 and -OH lead to Taniaphos-Cu-D-Phe is more stable than Taniaphos-Cu-L-Phe. This work provided a chiral extractant that has good abilities to enantioseparate various amino acid enantiomers.
Structure-guided engineering of: Pseudomonas dacunhae l-aspartate β-decarboxylase for l-homophenylalanine synthesis
Zhang, Min,Hu, Pengfei,Zheng, Yu-Cong,Zeng, Bu-Bing,Chen, Qi,Zhang, Zhi-Jun,Xu, Jian-He
, p. 13876 - 13879 (2020/11/18)
Structure-guided engineering of Pseudomonas dacunhael-aspartate β-decarboxylase (AspBDC) resulted in a double mutant (R37A/T382G) with remarkable 15400-fold improvement in specific activity reaching 216 mU mg-1, towards the target substrate 3(R)-benzyl-l-aspartate. A novel strategy for enzymatic synthesis of l-homophenylalanine was developed by using the variant as a biocatalyst affording 75% product yield within 12 h. Our results underscore the potential of engineered AspBDC for the biocatalytic synthesis of pharmaceutically relevant and value added unnatural l-amino acids.
Artificial Biocatalytic Cascade with Three Enzymes in One Pot for Asymmetric Synthesis of Chiral Unnatural Amino Acids
Zhou, Haisheng,Meng, Lijun,Yin, Xinjian,Liu, Yayun,Xu, Gang,Wu, Jianping,Wu, Mianbin,Yang, Lirong
supporting information, p. 6470 - 6477 (2019/11/02)
Two biocatalytic reactions, transamination catalyzed by transaminases and reductive amination catalyzed by amino acid dehydrogenases, can be used for asymmetric synthesis of optically pure unnatural amino acids. However, although transaminases show a great diversity and broad substrate spectrum, most transaminase reactions are reversible, while amino acid dehydrogenases catalyze reductive amination irreversibly but with strict substrate specificity. Accordingly, herein we developed a tri-enzyme one-pot reaction system to exploit the respective advantages of transaminases and amino acid dehydrogenases, while overcoming the disadvantages of each. In this work, representatives of all four subgroups of transaminases coupled with different amino acid dehydrogenases to produce five l- and four d- unnatural amino acid products, using ammonia and the co-enzyme NAD(P)H, which is regenerated by a robust alcohol dehydrogenase with 2-propanol as cheap cosubstrate. The complete conversion and high enantiopurity (ee > 99 %) of the products, demonstrated it as an ideal alternative for asymmetric synthesis of chiral amino acid compounds.