Biohydrolyses énantiosélectives catalysées par des Epoxydes Hydrolases (Application à la synthèse de 2-, 3- et 4-pyridyloxirannes optiquement purs)

AIX-MARSEILLE2-BU Sci.Luminy (130552106) / SudocSudocFranceF

Résolution cinétique d'époxydes fluorés par l'Hepoxyde Hydrolase d'Aspergillus niger

AIX-MARSEILLE2-BU Sci.Luminy (130552106) / SudocSudocFranceF

Enantioselective Inhibition Studies of the Cyclohexanone Monooxygenase from Acinetobacter SP NCIMB-9871

Cyclohexanone monooxygenase from Acinetobacter sp. NCIMB 9871 can be inhibited by bicyclic thiolactones. No evidence was obtained for enantioselective inhibition of the enzyme using this class of inhibitors in enantiomerically enriched form. This evidence supports the supposition that there is a single active site for this enzyme

Microbiological transformations. Part 48: Enantioselective biohydrolysis of 2-, 3- and 4-pyridyloxirane at high substrate concentration using the Agrobacterium radiobacter AD1 epoxide hydrolase and its Tyr215Phe mutant

The epoxide hydrolase (EH) from Agrobacterium radiobacter AD1 wild type (ArWT) and its Tyr215Phe mutant were compared for the biocatalyzed hydrolytic kinetic resolution (BHKR) of 2-, 3- and 4-pyridyloxirane. The regioselectivity of the oxirane ring opening as well as the substrate concentration limit and the inhibitory effect of the diol were determined. A gram scale preparation of enantiopure 2-pyridyloxirane (ee>98%) at a concentration as high as 127 mM (15.5 g/L) could be achieved with each of these two enzymes.

Biocatalytic Potential of the Epoxide Hydrolase from Agrobacterium radiobacter AD1 and a Mutant with Enhanced Enantioselectivity

Optically pure epoxides are useful synthons for a variety of biologically active compounds. The epoxide hydrolase obtained from Agrobacterium radiobacter AD1 hydrolyses racemic aryl epoxides with moderate and aliphatic epoxides with low enantioselectivity. The three-dimensional structure of this enzyme indicates that two tyrosine residues interact with the epoxide oxygen. Mutating one of these, tyrosine 215, to a phenylalanine (Y215F) resulted in an enzyme with increased enantioselectivity towards aryl epoxides. The relatively strong decrease in activity towards the remaining enantiomers makes this enzyme a much better biocatalyst than the wild-type enzyme for the preparation of optically pure (S)-styrene oxide derivatives.