@article{0e38a8d607ff48dea96e7584bc06bd5f,
title = "Negative supercoiling increases the sensitivity of plasmid DNA to single-Strand break induction by x-rays",
abstract = "Negatively supercoiled topoisomers of the plasmid pIBI 30 were irradiated with 250 kV X-rays and assayed for strand scission by agarose gel electrophoresis. The survival of supercoiled molecules (Form I) decreased exponentially with increasing X-ray exposure and the dose required to reduce the fraction of DNA in Form I to 37% of its value in unirradiated controls (D37) decreased with increasing negative superhelicity. This enhanced radiation sensitivity of underwound DNA is tentatively attributed to the transient denaturation of the double helix that increases the susceptibility of individual strands to free radical attack.",
author = "Miller, {J. H.} and Nelson, {J. M.} and M. Ye and Swenberg, {C. E.} and Speicher, {J. M.} and Benham, {C. J.}",
note = "Funding Information: Acknowledgements The authors gratefully acknowledge support for this work by the Office of Health and Environmental Research (OHER) US Department of Energy under contract DE-AC06-76RLO 1830, the Armed Forces Radiobiology Research Institute, and grant DMB 88-96284 from the National Science Foundation (CJB) . We also acknowledge the contributions of Professor E . W . Fleck, Whitman College, Walla Walla, WA, to this work through both helpful discussions and assistance with experimental procedures .",
year = "1991",
doi = "10.1080/09553009114550831",
language = "English",
volume = "59",
pages = "941--949",
journal = "International Journal of Radiation Biology",
issn = "0955-3002",
publisher = "Informa Healthcare",
number = "4",
}