Strand breaks, base release, and postirradiation changes in DNA. gamma. -irradiated in dilute Q/sub 2/-saturated aqueous solution
..gamma..-Irradiation of DNA in dilute O/sub 2/-saturated aqueous solution releases free bases and damaged bases from the macromolecule. The yields of these products were measured after column chromatographic separation. For double-stranded DNA the immediate yield of bases varies from G = 0.012 for cytosine to G = 0.033 for adenine. The yields of released bases increase with postirradiation time (the majority of the increase occurs in the first 2 hr) to yields in the range of G = 0.07 to +-0.012. Yields of two released damaged thymine radiation products from ..gamma..-irradiated /sup 3/H thymine-labeled DNA also increased with postirradiation time. Strand breaks were measured in ..gamma..-irradiated single-stranded DNA; the initial yield G = 0.02 was low but increased with time to G = 0.07. No direct correlation between strand-break production and release of products of low molecular weight is possible. The findings are discussed in terms of damage to DNA in vivo and its enzymatic repair.
- Research Organization:
- Univ. of California, Los Angeles
- OSTI ID:
- 7343077
- Journal Information:
- Radiat. Res.; (United States), Vol. 66:3
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DNA
BIOLOGICAL RADIATION EFFECTS
STRAND BREAKS
RADIOINDUCTION
AQUEOUS SOLUTIONS
BASES
BIOLOGICAL REPAIR
G VALUE
GAMMA RADIATION
IRRADIATION
OXYGEN
BIOLOGICAL EFFECTS
BIOLOGICAL RECOVERY
CRYOGENIC FLUIDS
DISPERSIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUIDS
IONIZING RADIATIONS
MIXTURES
NONMETALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
SOLUTIONS
560111* - Radiation Effects on Biochemicals- In Vitro- (-1987)