Abstract
The sites of cleavage of DNA by bleomycin A2, bleomycin B2, phleomycin, tallysomycin A, and Blenoxane (Bristol-Meyers) in reactions containing equimolar Fe2+ and atmospheric oxygen were analyzed by gel electrophoresis of 32P end labeled DNA fragments. Bleomycin A2 and bleomycin B2 reactions cleaved DNA at all sites with a frequency equal to that of Blenoxane. At high concentrations of bleomycin the site specificity of cleavage was unchanged. Bleomycin cleavage sites and phleomycin cleavage sites are a subset of sites cleaved in reactions containing tallysomycin A. The nature of 5’ and 3’ termini induced by bleomycin cleavage was investigated. Electrophoresis of bleomycin-induced fragments after alkaline phosphatase or polynucleotide kinase treatment indicated that 5’ termini are phosphoryl groups but 3’ termini are not simple phosphoryl groups. Analysis of bleomycin cleavage of single-stranded DNA substrate showed that cleavage occurs only in regions of potentially double-stranded looped-back sequences. Possible mechanisms for determination of bleomycin cleavage sequence specificity are discussed.
Original language | English (US) |
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Pages (from-to) | 4310-4318 |
Number of pages | 9 |
Journal | Biochemistry |
Volume | 21 |
Issue number | 18 |
DOIs | |
State | Published - Aug 1982 |
Externally published | Yes |
ASJC Scopus subject areas
- Biochemistry