Author: Skalden, L.; Peters, C.; Dickerhoff, J.; Nobili, A.; Joosten, H.-J.; Weisz, K.; Hohne, M.; Bornscheuer, U.T.
Description: Amine transaminases (ATAs) are powerful enzymes for the stereospecific production of chiral amines. However, the synthesis of amines incorporating more than one stereocenter is still a challenge. We developed a cascade synthesis to access optically active 3-alkyl-substituted chiral amines by combining two asymmetric synthesis steps catalyzed by an enoate reductase and ATAs. The ATA wild type from Vibrio fluvialis showed only modest enantioselectivity (14 % de) in the amination of (S)-3-methylcyclohexanone, the product of the enoate-reductase-catalyzed reaction step. However, by protein engineering we created two variants with substantially improved diastereoselectivities: variant Leu56Val exhibited a higher R selectivity (66 % de) whereas the Leu56Ile substitution caused a switch in enantiopreference to furnish the S-configured diastereomer (70 % de). Addition of 30 % DMSO further improved the selectivity and facilitated the synthesis of (1R,3S)-1-amino-3-methylcyclohexane with 89 % de at 87 % conversion.
Subject Headings: Amines/metabolism; Amino Acid Substitution; Models, Molecular; Protein Conformation; Stereoisomerism; Substrate Specificity; Transaminases/chemistry/genetics/metabolism; Vibrio/enzymology; amine transaminases; cascade synthesis; enantiopreference; enzyme catalysis; protein engineering
Subject headings:
Publication year: 2015
Journal or book title: Chembiochem : a European Journal of Chemical Biology
Volume: 16
Issue: 7
Pages: 1041-1045
Find the full text :Â https://chemistry-europe.onlinelibrary.wiley.com/doi/abs/10.1002/cbic.201500074
Find more like this one (cited by): https://scholar.google.com/scholar?cites=8631321975936686855&as_sdt=1000005&sciodt=0,16&hl=en
Type: Journal Article
Serial number: 2203