Enhancing a Sphaerobacter thermophilus ω-transaminase for kinetic resolution of β- and γ-amino acids

AMB Express

Original Article

Rüdiger Bode¹  Ina Lemke²  Falko Matthes²  Gotthard Kunze²  Uwe Wegner²  Nicolaus von Wirén²  Marion Rauter³  H.-Matthias Vorbrodt³ 

[1] Institute of Microbiology, University of Greifswald, Jahnstr. 15, 17487, Greifswald, Germany;Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr. 3, 06466, Seeland, OT Gatersleben, Germany;Orgentis Chemicals GmbH, Bahnhofstr. 3-5, 06466, Seeland, OT Gatersleben, Germany;

关键词: ω-Transaminase;    Sphaerobacter thermophilus;    Optimization;    ß- and γ-amino acids;    Kinetic resolution;   

DOI  :  10.1186/s13568-023-01623-x

 received in 2023-07-17, accepted in 2023-10-03,  发布年份 2023

来源: Springer

【 摘 要 】

Sphaerobacter thermophilus synthesizes an ω-transaminase (ω-TA) that allows the production of enantiomerically pure β-amino acids. To obtain ω-TA variants with a higher activity and more favorable properties for industrial use, we modified critical amino acid residues either in the catalytic center or in a previously proposed signature motif critical for aromatic β-amino acid ω-TAs. Seventeen different variants of this enzyme were generated and their activity was examined with four β-amino acids and one γ-amino acid, and compared with the wildtype’s activity. Among all variants, seven showed up to ninefold higher activity with at least one of the tested substrates. For most of these seven variants, the temperature optimum was even lower as in the wild type enzyme, with keeping a high temperature stability, making them more valuable for industrial purposes. Our results indicate that for the production of enantiomerically pure β-amino acids replacement of critical amino acid residues in the proposed signature motif of ω-TAs is a more effective strategy than modifying their catalytic center. Another finding was, that the proposed motif is not only suitable for aromatic amino acid ω-TAs, because some of the variants have a higher activity with β-alanine or β-leucine than with aromatic β-amino acids.Graphical Abstract

【 授权许可】

CC BY   
© Springer-Verlag GmbH Germany, part of Springer Nature 2023

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