Radiation-induced DNA damage as a function of DNA hydration

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:400723

Swarts, S G; Miao, L; Wheeler, K T ^[1]; Sevilla, M D; Becker, D ^[2]

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1. Bowman Gray School of Medicine, Winston-Salem, NC (United States). Dept. of Radiology
2. Oakland Univ., Rochester, MI (United States). Dept. of Chemistry

Radiation-induced DNA damage is produced from the sum of the radicals generated by the direct ionization of the DNA (direct effect) and by the reactions of the DNA with free radicals formed in the surrounding environment (indirect effect). The indirect effect has been believed to be the predominant contributor to radiation-induced intracellular DNA damage, mainly as the result of reactions of bulk water radicals (e.g., OH{center_dot}) with DNA. However, recent evidence suggests that DNA damage, derived from the irradiation of water molecules that are tightly bound in the hydration layer, may occur as the result of the transfer of electron-loss centers (e.g. holes) and electrons from these water molecules to the DNA. Since this mechanism for damaging DNA more closely parallels that of the direct effect, the irradiation of these tightly bound water molecules may contribute to a quasi-direct effect. These water molecules comprise a large fraction of the water surrounding intracellular DNA and could account for a significant proportion of intracellular radiation-induced DNA damage. Consequently, the authors have attempted to characterize this quasi-direct effect to determine: (1) the extent of the DNA hydration layer that is involved with this effect, and (2) what influence this effect has on the types and quantities of radiation-induced DNA damage.

• DOE Contract Number: FG02-86ER60455
• OSTI ID: 400723
• Report Number(s): CONF-9410280--; ISBN 0-935470-90-5
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL RADIATION EFFECTS
DNA
HYDRATION
MOLECULAR STRUCTURE
RADICALS