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Improving the catalytic performance of an artificial metalloenzyme by computational design

Heinisch, Tillmann and Pellizzoni, Michaela and Dürrenberger, Marc and Tinberg, Christine E. and Köhler, Valentin and Häussinger, Daniel and Klehr, Juliane and Baker, David and Ward, Thomas R.. (2015) Improving the catalytic performance of an artificial metalloenzyme by computational design. Journal of the American Chemical Society, 137 (32). pp. 10414-10419.

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Official URL: http://edoc.unibas.ch/40384/

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Abstract

Artifical metalloenzymes combine the reactivity of small molecule catalysts with the selectivity of enzymes, and new methods are required to tune the catalytic properties of these systems for an application of interest. Structure-based computational design could help to identify amino acid mutations leading to improved catalytic activity and enantioselectivity. Here we describe the application of Rosetta Design for the genetic optimization of an artificial transfer hydrogenase (ATHase hereafter), [(η(5)-Cp*)Ir(pico)Cl] ⊂ WT hCA II (Cp* = Me5C5(-)), for the asymmetric reduction of a cyclic imine, the precursor of salsolsidine. Based on a crystal structure of the ATHase, computational design afforded four hCAII variants with protein backbone-stabilizing and hydrophobic cofactor-embedding mutations. In dansylamide-competition assays, these designs showed 46-64-fold improved affinity for the iridium pianostool complex [(η(5)-Cp*)Ir(pico)Cl]. Gratifyingly, the new designs yielded a significant improvement in both activity and enantioselectivity (from 70% ee (WT hCA II) to up to 92% ee and a 4-fold increase in total turnover number) for the production of (S)-salsolidine. Introducing additional hydrophobicity in the Cp*-moiety of the Ir-catalyst provided by adding a propyl substituent on the Cp* moiety yields the most (S)-selective (96% ee) ATHase reported to date. X-ray structural data indicate that the high enantioselectivity results from embedding the piano stool moiety within the protein, consistent with the computational model.
Faculties and Departments:05 Faculty of Science > Departement Chemie
05 Faculty of Science > Departement Chemie > Chemie > Bioanorganische Chemie (Ward)
05 Faculty of Science > Departement Chemie > Chemie > Nuclear Magnetic Resonance (Häussinger)
UniBasel Contributors:Ward, Thomas R. and Heinisch, Tillmann and Dürrenberger, Marc and Köhler, Valentin and Pellizzoni, Michela Maria and Häussinger, Daniel and Klehr, Juliane
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:American Chemical Society
ISSN:0002-7863
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Identification Number:
Last Modified:18 Sep 2017 09:26
Deposited On:03 May 2016 13:17

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