Portal de Periódicos da CAPES

Bleomycin A2: a ferrous oxidase.

1979; National Institutes of Health; Volume: 16; Issue: 1 Linguagem: Inglês

Caspary Wj, Craig Niziak, Lanzo Da, Rosalind D. Friedman, Bachur Nr,

Advanced biosensing and bioanalysis techniques

The bleomycins are polypeptides produced by Streptomyces verticullus and are used in chemotherapy of various malignancies. We find that bleomycin A 2 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 A 2 turns over approximately 5,000 moles Fe ++ /min. This catalytic activity of bleomycin A 2 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.