Purification of bromoperoxidase from Pseudomonas aureofaciens.

A Bromoperoxidase has been isolated and purified from Pseudomonas aureofaciens ATCC 15926 mutant strain ACN. The purified enzyme was homogeneous as determined by polyacrylamide gel electrophoresis and ultracentrifugation. This bromoperoxidase can utilize bromide ions in the presence of hydrogen peroxide and a halogen acceptor for the catalytic formation of carbon-halogen bonds. The homogeneous enzyme also has peroxidase and catalase activity. Based on the results from gel filtration and ultracentrifugation, the molecular weight of this procaryotic bromoperoxidase is 155,000 to 158,000. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows a single band having the mobility of a 77,000-molecular-weight species. We thus conclude that this bromoperoxidase exists in solution as a dimeric species. The heme prosthetic group of bromoperoxidase is ferriprotoporphyrin IX. The spectral properties of the native and reduced enzyme are reported. This bromoperoxidase is the first halogenating enzyme purified from procaryotic sources.