Isolation and characterization of a novel nonheme chloroperoxidase.

Chloroperoxidase, purified from the fermentation of Curvularia inaequalis, had a molecular weight of approximately 240,000 and was composed of 4 subunits of identical molecular weight (Mr 66,000). The enzyme was specific for I-, Br- and Cl-, and inactive toward F-. The optimum pH of the enzyme was centered around 5.0. X-ray fluorescence revealed that the enzyme contained 2.2 atoms of zinc and 0.7 atom of Fe per molecule of protein. The enzyme had no heme-like compound as a prosthetic group, making it the first nonheme chloroperoxidase to be reported. Under oxidative conditions that rapidly inactivated other haloperoxidases, this enzyme was remarkably stable.