title: An (R)-Imine Reductase Biocatalyst for the Asymmetric Reduction of Cyclic Imines.
abstract: Although the range of biocatalysts available for the synthesis of enantiomerically pure chiral amines continues to expand, few existing methods provide access to secondary amines. To address this shortcoming, we have over-expressed the gene for an (R)-imine reductase [(R)-IRED] fromStreptomycessp. GF3587 inEscherichia colito create a recombinant whole-cell biocatalyst for the asymmetric reduction of prochiral imines. The (R)-IRED was screened against a panel of cyclic imines and two iminium ions and was shown to possess high catalytic activity and enantioselectivity. Preparative-scale synthesis of the alkaloid (R)-coniine (90 % yield; 99 %ee) from the imine precursor was performed on a gram-scale. A homology model of the enzyme active site, based on the structure of a closely related (R)-IRED fromStreptomyces kanamyceticus, was constructed and used to identify potential amino acids as targets for mutagenesis.
authors.affiliation: School of Chemistry, University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester, M1 7DN (UK).
authors.forename: Shahed
authors.initials: S
authors.lastname: Hussain
authors.affiliation: School of Chemistry, University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester, M1 7DN (UK).
authors.forename: Friedemann
authors.initials: F
authors.lastname: Leipold
authors.affiliation: Department of Chemistry, University of York, Heslington, York, YO10 5DD (UK).
authors.forename: Henry
authors.initials: H
authors.lastname: Man
authors.affiliation: Department of Chemistry, University of York, Heslington, York, YO10 5DD (UK).
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Wells
authors.affiliation: School of Chemistry, University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester, M1 7DN (UK).
authors.forename: Scott P
authors.initials: SP
authors.lastname: France
authors.affiliation: Chemical Development, AstraZeneca, Silk Rd Business Park, Macclesfield SK10 2NA (UK).
authors.forename: Keith R
authors.initials: KR
authors.lastname: Mulholland
authors.affiliation: Department of Chemistry, University of York, Heslington, York, YO10 5DD (UK).
authors.forename: Gideon
authors.initials: G
authors.lastname: Grogan
authors.affiliation: School of Chemistry, University of Manchester, Manchester Institute of Biotechnology, 131 Princess Street, Manchester, M1 7DN (UK).
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Turner
keywords: amines; asymmetric catalysis; biocatalysis; nitrogen heterocycles; reduction