title: Hyperthermic modification of bleomycin--DNA interaction detected by electron spin resonance.
abstract: Electron spin resonance spectra of DNA labeled with each of four spin-labeling compounds have been studied to detect interaction between the antibiotic bleomycin and DNA. Only one of these labels, compound IV, resulted in a modified spectrum when bound to DNA and the latter was subjected to bleomycin. This property has been used to monitor DNA-bleomycin interactions under physiological and hyperthermic conditions. Bleomycin produced an increase in rotational correlation time of the residue bound to DNA at 37 degrees C and a significantly higher increase at 43 degrees C. Some effect was still detected with bleomycin at 37 degrees C after preheating at 43 degrees C. Parallel studies have revealed enhanced binding of 59Fe-bleomycin to DNA during and after hyperthermic treatment.
mesh_terms: D001761:Bleomycin / Q000032:analysis / Q000494:pharmacology*; D004247:DNA / Q000032:analysis / Q000494:pharmacology*; D004347:Drug Interactions; D004578:Electron Spin Resonance Spectroscopy; D006358:Hot Temperature; D013113:Spin Labels; D013696:Temperature
chemical_list: D013113:Spin Labels; D001761:Bleomycin; D004247:DNA