Purification and properties of a non-haem chloroperoxidase from Serratia marcescens.

A non-haem chloroperoxidase was isolated from the enteric bacterium Serratia marcescens. The enzyme was purified to homogeneity by heat treatment, ammonium sulfate precipitation, ion exchange chromatography, gel filtration and dye-ligand affinity chromatography. Native chloroperoxidase has a molecular mass of 58 kDa and consists of two identical subunits of 29 kDa. Whereas chloroperoxidase catalyses only the bromination of monochlorodimedone, indole is chlorinated by this enzyme. Chloroperoxidase also catalyses the oxidation of amino to nitro groups. The enzyme is thermostable and does not lose any activity when incubated at 65 degrees C for 2 h. Comparison of the first 15 amino-terminal amino acids showed a sequence identity of 80% to the chloroperoxidases from Streptomyces lividans and Pseudomonas pyrrocinia. However, no precipitation band was obtained in the Ouchterlony agar diffusion assay with antibodies raised against the chloroperoxidases from Pseudomonas pyrrocinia and Streptomyces aureofaciens Tü24.