title: Stereoselective C-C bond formation catalysed by engineered carboxymethylproline synthases.
abstract: The reaction of enol(ate)s with electrophiles is used extensively in organic synthesis for stereoselective C-C bond formation. Protein-based catalysts have had comparatively limited application for the stereoselective formation of C-C bonds of choice via enolate chemistry. We describe protein engineering studies on 5-carboxymethylproline synthases, members of the crotonase superfamily, aimed at enabling stereoselective C-C bond formation leading to N-heterocycles via control of trisubstituted enolate intermediates. Active site substitutions, including at the oxyanion binding site, enable the production of substituted N-heterocycles in high diastereomeric excesses via stereocontrolled enolate formation and reaction. The results reveal the potential of the ubiquitous crotonase superfamily as adaptable catalysts for the control of enolate chemistry.
authors.affiliation: Department of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, UK.
authors.forename: Refaat B
authors.initials: RB
authors.lastname: Hamed
authors.forename: J Ruben
authors.initials: JR
authors.lastname: Gomez-Castellanos
authors.forename: Armin
authors.initials: A
authors.lastname: Thalhammer
authors.forename: Daniel
authors.initials: D
authors.lastname: Harding
authors.forename: Christian
authors.initials: C
authors.lastname: Ducho
authors.forename: Timothy D W
authors.initials: TD
authors.lastname: Claridge
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Schofield
mesh_terms: D000595:Amino Acid Sequence; D002244:Carbon / Q000378:metabolism*; D019755:Carbon-Carbon Lyases / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D020134:Catalytic Domain; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D015202:Protein Engineering; D017386:Sequence Homology, Amino Acid
chemical_list: D002244:Carbon; D019755:Carbon-Carbon Lyases; C484323:carboxymethylproline synthase