Activated bleomycin. A transient complex of drug, iron, and oxygen that degrades DNA.

R. M. Burger, J. Peisach, S. B. Horwitz

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301 Scopus citations


"Activated bleomycin" is an oxygenated iron drug complex which embodies the drug's DNA-cleaving activity. This activity is exercised on DNA, if present, but if DNA is absent, the drug itself is inactivated. Hyperfine interactions in the EPR spectra of activated bleomycin prepared with 57Fe(II) and 17O2 demonstrate the presence of iron as Fe(III) and of bound oxygen originating in dioxygen. Bleomycin can also be activated with Fe(III) and either H2O2 or ethyl hydroperoxide. These latter reactions do not produce a ferrous intermediate nor do they require O2. But O2 is required for the reaction of activated bleomycin with DNA to yield the malondialdehyde-like chromogens used to monitor DNA degradation. The attack on DNA is quantitatively concurrent with the decay of activated bleomycin, however generated.

Original languageEnglish (US)
Pages (from-to)11636-11644
Number of pages9
JournalJournal of Biological Chemistry
Issue number22
StatePublished - Nov 25 1981
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


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