A Reductive Aminase Switches to Imine Reductase Mode for a Bulky Amine Substrate.

Autor:	Gilio AK; Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Thorpe TW; School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K., Heyam A; Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Petchey MR; Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., Pogrányi B; Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K., France SP; Pfizer Worldwide Research and Development, 445 Eastern Point Road, Groton, Connecticut 06340, United States., Howard RM; Pfizer Worldwide Research and Development, 445 Eastern Point Road, Groton, Connecticut 06340, United States., Karmilowicz MJ; Pfizer Worldwide Research and Development, 445 Eastern Point Road, Groton, Connecticut 06340, United States., Lewis R; Pfizer Worldwide Research and Development, 445 Eastern Point Road, Groton, Connecticut 06340, United States., Turner N; School of Chemistry, Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester M1 7DN, U.K., Grogan G; Department of Chemistry, University of York, Heslington, York YO10 5DD, U.K.
Jazyk:	angličtina
Zdroj:	ACS catalysis [ACS Catal] 2023 Jan 12; Vol. 13 (3), pp. 1669-1677. Date of Electronic Publication: 2023 Jan 12 (Print Publication: 2023).
DOI:	10.1021/acscatal.2c06066
Abstrakt:	Imine reductases (IREDs) catalyze the asymmetric reduction of cyclic imines, but also in some cases the coupling of ketones and amines to form secondary amine products in an enzyme-catalyzed reductive amination (RedAm) reaction. Enzymatic RedAm reactions have typically used small hydrophobic amines, but many interesting pharmaceutical targets require that larger amines be used in these coupling reactions. Following the identification of IR77 from Ensifer adhaerens as a promising biocatalyst for the reductive amination of cyclohexanone with pyrrolidine, we have characterized the ability of this enzyme to catalyze couplings with larger bicyclic amines such as isoindoline and octahydrocyclopenta( c )pyrrole. By comparing the activity of IR77 with reductions using sodium cyanoborohydride in water, it was shown that, while the coupling of cyclohexanone and pyrrolidine involved at least some element of reductive amination, the amination with the larger amines likely occurred ex situ, with the imine recruited from solution for enzyme reduction. The structure of IR77 was determined, and using this as a basis, structure-guided mutagenesis, coupled with point mutations selecting improving amino acid sites suggested by other groups, permitted the identification of a mutant A208N with improved activity for amine product formation. Improvements in conversion were attributed to greater enzyme stability as revealed by X-ray crystallography and nano differential scanning fluorimetry. The mutant IR77-A208N was applied to the preparative scale amination of cyclohexanone at 50 mM concentration, with 1.2 equiv of three larger amines, in isolated yields of up to 93%. Competing Interests: The authors declare the following competing financial interest(s): Mark Petchey is currently a Postdoctoral Researcher at AstraZeneca R&D Gothenburg. (© 2023 The Authors. Published by American Chemical Society.)
Databáze:	MEDLINE
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