Partial purification, stereospecificity and stoichiometry of three dehalogenases from a Rhizobium species

Abstract

A fast-growing species of Rhizobium that utilized 2,2-dichloropropionate (2,2DCP) and D,L-2-chloropropionate (DL-2CP) as sole sources of carbon and energy was shown to contain three inducible dehalogenases. These enzymes differed in their substrate specificities: dehalogenase II degraded 2,2DCP, D- and L-2CP, monochloroacetate (MCA) and dichloroacetate (DCA) whilst dehalogenase I showed activity only towards L-2CP and DCA. Dehalogenase III liberated halide from D-2CP and MCA. This is the first report of a dehalogenase acting solely on the D-isomer of a haloalkanoate. All three dehalogenases inverted the isomeric configuration during dehalogenation, forming D(-) and L(+) lactate from L- and D-2CP, respectively. © 1988.