Effect of aqueous free radicals and cis-dichlorodiammineplatinum(II) on radiation-induced base release from DNA

Journal Article · Tue Dec 01 04:00:00 EST 1981 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3575637· OSTI ID:5572080

Richmond, R C ^[1]; Kelman, A D

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1. Dartmouth-Hitchcock Medical Center, Hanover, N.H.

The radiation-induced release of (Me-/sup 3/H)thymine residues from purified Escherichia coli DNA irradiated in aqueous solution has been characterized by gel filtration. This yield of thymine residues is reduced by the presence of t-butanol or cis-dichlorodiammineplatinum (II) (cis-DDP) when samples are equilibrated with air, N/sub 2/, or N/sub 2/O, with the one exception that the yield of thymine base is unaltered by the presence of cis-DDP in N/sub 2/O-gassed solution. The OH radical reaction with DNA is the major pathway leading to thymine residue release, and the Pt(III) intermediate reacts in an analogous fashion to liberate thymine base specifically. The Pt(I) intermediate, though at half the Pt(III) efficiency, also causes the specific release of thymine base. In aerated solutions, the degree of reduction in radiation-induced thymine residue release caused by cis-DDP is in excess of that expected due to the scavenging of OH radicals by this platinum complex. cis-DDP reduction of the thymine residue yields must involve a mechanism that operates in addition to the scavenging of the OH radical. The Pt(I) intermediate is assessed to be the most likely species involved in the radiation sensitization of hypoxic cells, and its effect on thymine residue release in these experiments is evaluated.

• OSTI ID: 5572080
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 88:3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560112* -- Radiation Effects on Biochemicals-- In Microorganisms-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AIR
AZINES
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CHALCOGENIDES
DAMAGE
DNA
ELEMENTS
ESCHERICHIA COLI
FILTRATION
FLUIDS
GASES
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
LABELLED COMPOUNDS
MICROORGANISMS
NITROGEN
NITROGEN COMPOUNDS
NITROGEN OXIDES
NONMETALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM COMPOUNDS
PYRIMIDINES
RADIATION EFFECTS
RADICALS
RESPONSE MODIFYING FACTORS
SEPARATION PROCESSES
THYMINE
TRANSITION ELEMENT COMPOUNDS
TRITIUM COMPOUNDS
URACILS