DECREASE OF MELTING TEMPERATURE AND SINGLE STRAND SCISSION OF DNA BY BLEOMYCIN IN PRESENCE OF HYDROGEN PEROXIDE

Effect of bleomycin and H2O2 on DNA was investigated. Tm of salmon sperm DNA decreased from 76°C to 64°C and that of Escherichia colt DNA from 81°C to 65.5°C in the presence of 100 μM of H2O2 and 4μg/ml of bleomycin. The change of Tm was more marked when the concentration of H2O2 or bleomycin was increased. The single strand scission of DNA was shown when the DNA was incubated at 37°C with 100/μlM of H2O2and 40 μg/ml of bleomycin. It proceeded as the time of incubation was prolonged. The reaction of H2O2 at 100μm on DNA was apparent only in the presence of bleomycin. © 1969, JAPAN ANTIBIOTICS RESEARCH ASSOCIATION. All rights reserved.