Bleomycin congeners exhibiting altered DNA cleavage specificity

The bleomycins (BLM's) are a family of structurally complex glycoprotein antibiotics possessing significant anticancer activity. Reported herein is an analysis of DNA cleavage by seven BLM congeners that establishes the existence of significant differences in the patterns of DNA cleavage. This finding provides important insights concerning the structural factors that control sequence selectivity, further supports the representation of activated Fe multiplied by BLM as a high valent metal-oxo complex, and may bear relevance to the design of a BLM congener having an altered spectrum of antitumor activity.