title: Enzyme-Modified Particles for Selective Biocatalytic Hydrogenation by Hydrogen-Driven NADH Recycling.
abstract: We describe a new approach to selective H2-driven hydrogenation that exploits a sequence of enzymes immobilised on carbon particles. We used a catalyst system that comprised alcohol dehydrogenase, hydrogenase and an NAD+reductase on carbon black to demonstrate a greater than 98 % conversion of acetophenone to phenylethanol. Oxidation of H2by the hydrogenase provides electrons through the carbon for NAD+reduction to recycle the NADH cofactor required by the alcohol dehydrogenase. This biocatalytic system operates over the pH range 6-8 or in un-buffered water, and can function at low concentrations of the cofactor (10 μm NAD+) and at H2partial pressures below 1 bar. Total turnover numbers >130 000 during acetophenone reduction indicate high enzyme stability, and the immobilised enzymes can be recovered by a simple centrifugation step and re-used several times. This offers a route to convenient, atom-efficient operation of NADH-dependent oxidoreductases for selective hydrogenation catalysis.
authors.affiliation: Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road, Oxford, OX1 3QR (UK) E-mail: kylie.vincent@chem.ox.ac.uk.
authors.forename: Holly A
authors.initials: HA
authors.lastname: Reeve
authors.affiliation: Institute of Chemistry, Technische Universität Berlin Strasse des 17. Juni 135, 10623, Berlin (Germany).
authors.forename: Lars
authors.initials: L
authors.lastname: Lauterbach
authors.affiliation: Institute of Chemistry, Technische Universität Berlin Strasse des 17. Juni 135, 10623, Berlin (Germany).
authors.forename: Oliver
authors.initials: O
authors.lastname: Lenz
authors.affiliation: Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory South Parks Road, Oxford, OX1 3QR (UK) E-mail: kylie.vincent@chem.ox.ac.uk.
authors.forename: Kylie A
authors.initials: KA
authors.lastname: Vincent
keywords: biocatalysis; biotransformations; enzyme catalysis; heterogeneous catalysis; hydrogenation