PURIFICATION AND CHARACTERIZATION OF D-2-HALOACID DEHALOGENASE FROM PSEUDOMONAS-PUTIDA STRAIN AJ1/23

A D-2 haloacid dehalogenase was isolated and purified to homogeneity from Pseudomonas putida strain AJ1/23. The enzyme catalysed the stereospecific dehalogenation of the D-isomer of 2-chloropropionate. Using a new ion-chromatograph assay, the enzyme was found to catalyse the dehalogenation of short-chain 2-halocarboxylic acids. Maximum enzyme activity occurred at pH 9.5 and 50°C and the enzyme was insensitive to most -SH reagents. The enzyme has an M(r) of about 135000 and appears to be composed of four subunits of identical M(r).