Browsing by Subject ""Michaelase""
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    Enantioselective Synthesis of Pharmaceutically Active γ-Aminobutyric Acids Using a Tailor-Made Artificial Michaelase in One-Pot Cascade Reactions
    ( 2019-02-01) Biewenga, Lieuwe ; Saravanan, Thangavelu ; Kunzendorf, Andreas ; Van Der Meer, Jan Ytzen ; Pijning, Tjaard ; Tepper, Pieter G. ; Van Merkerk, Ronald ; Charnock, Simon J. ; Thunnissen, Andy Mark W.H. ; Poelarends, Gerrit J.
    Chiral γ-aminobutyric acid (GABA) analogues represent abundantly prescribed drugs, which are broadly applied as anticonvulsants, as antidepressants, and for the treatment of neuropathic pain. Here we report a one-pot two-step biocatalytic cascade route for synthesis of the pharmaceutically relevant enantiomers of γ-nitrobutyric acids, starting from simple precursors (acetaldehyde and nitroalkenes), using a tailor-made highly enantioselective artificial "Michaelase" (4-oxalocrotonate tautomerase mutant L8Y/M45Y/F50A), an aldehyde dehydrogenase with a broad non-natural substrate scope, and a cofactor recycling system. We also report a three-step chemoenzymatic cascade route for the efficient chemical reduction of enzymatically prepared γ-nitrobutyric acids into GABA analogues in one pot, achieving high enantiopurity (e.r. up to 99:1) and high overall yields (up to 70%). This chemoenzymatic methodology offers a step-economic alternative route to important pharmaceutically active GABA analogues, and highlights the exciting opportunities available for combining chemocatalysts, natural enzymes, and designed artificial biocatalysts in multistep syntheses.