Purification and Characterization of Two Haloperoxidases from the Glycopeptide Antibiotic ProducerStreptomyces toyocaensisNRRL 15009

Streptomyces toyocaensis NRRL 15009 produces A47934, a glycopeptide antibiotic. This compound is composed of several unusual amino acids, some of which have chlorinated aromatic rings. We have isolated two distinct halogenating enzymes, a chloroperoxidase (42,882 Da) and a catalase/bromoperoxidase (53,890 Da), from late log phase drug producing cultures of this organism grown on soy based media. Both these enzymes are azide sensitive and show absorption spectra consistent with the presence of an iron-heme group. We have characterized these enzymes with respect to substrate specificity, steady state kinetics, molecular mass and N-terminal sequence. The catalase/bromoperoxidase is similar to an enzyme from the chloramphenicol producer, Streptomyces venezuelae, while the chloroperoxidase is a unique protein.