The enantioselectivity of haloalkane dehalogenases

Two haloalkane dehalogenases were tested for their ability to perform kinet ic resolutions of a series of racemic substrates and to convert meso substr ates enantioselectively. For the kinetic resolutions E-values of up to 9 we re measured and, in the conversions of the meso substrates, products were o btained with an enantiomeric excess of up to 47%. A kinetic analysis reveal ed that despite modest overall chiral recognition (expressed as E-values), there are large differences between the K-m values (>100 fold) of two enant iomeric substrates but that these differences are compensated by correspond ingly large differences in k(cat). (C) 2001 Elsevier Science Ltd. All right s reserved.