PT - JOURNAL ARTICLE AU - WILLIAM J. CASPARY AU - CRAIG NIZIAK AU - D. ALLAN LANZO AU - ROSALIND FRIEDMAN AU - NICHOLAS R. BACHUR TI - Bleomycin A<sub>2</sub>: A Ferrous Oxidase DP - 1979 Jul 01 TA - Molecular Pharmacology PG - 256--260 VI - 16 IP - 1 4099 - http://molpharm.aspetjournals.org/content/16/1/256.short 4100 - http://molpharm.aspetjournals.org/content/16/1/256.full SO - Mol Pharmacol1979 Jul 01; 16 AB - The bleomycins are polypeptides produced by Streptomyces verticullus and are used in chemotherapy of various malignancies. We find that bleomycin A2 catalyzes the oxidation of Fe++ to Fe+++ and reduces oxygen. The reaction follows classical Michaelis-Menten kinetics (Vmax = 0.27 µmole/min/ml, Km = 1.8 mM). One mole of bleomycin A2 turns over approximately 5,000 moles Fe++/min. This catalytic activity of bleomycin A2 is heat insensitive and strongly dependent on pH, buffer and ionic strength, and is unaffected by DNA. This enzyme-like action may be involved in the bleomycin degradation of DNA.