Single-strand breaks in double-stranded DNA irradiated in anoxic solution: Contribution of tert-butanol radicals
- Max-Planck-Institut fuer Strahlenchemis, Ruhr (Germany)
Yields of single-strand breaks induced by {sup 60}Co {gamma} or pulse irradiation in double-stranded calf thymus DNA have been measured in N{sub 2}O-saturated aqueous solution as a function of the concentration of tert-butanol. The yields were found to be dependent on dose rate. The experimental data were analyzed using a theoretical model based on non-homogeneous scavenging kinetics. It is concluded from this analysis after {sup 60}Co {gamma} irradiation in the absence of oxygen, aside from breaks caused by hydroxyl radicals, additional breaks occur which are initiated by hydrogen atoms and secondary radicals of tert-butanol. The efficiency of hydrogen atoms in causing single-strand breaks in double-stranded calf thymus DNA was determined to be 2.3%, while the rate constant for the reaction of tert-butanol radicals with DNA and their efficiency in causing single-strand breaks was determined to be 4.1 x 10{sup 3} dm{sup 3} mol{sup -1} s{sup -1} and 2%, respectively. 37 refs., 2 figs., 2 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 381019
- Journal Information:
- Radiation Research, Journal Name: Radiation Research Journal Issue: 2 Vol. 146; ISSN 0033-7587; ISSN RAREAE
- Country of Publication:
- United States
- Language:
- English
Similar Records
Yields of single-strand breaks in double-stranded calf thymus DNA irradiated in aqueous solution in the presence of oxygen and scavengers
Free radical-induced chain breakage in irradiated aqueous solutions of DNA