Linked Life Data

1672357

Source:http://linkedlifedata.com/resource/pubmed/id/1672357

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-4-22
pubmed:abstractText
The yield of single-strand breaks induced by 60Co gamma-radiation in single-stranded calf-thymus DNA has been measured in aqueous, N2O/O2 saturated DNA solutions as a function of the concentration of added OH scavengers. Single-strand break yields have also been determined, relative to the yield of OH radicals, using pulse radiolysis. Essentially the same dependence on scavenging capacity was obtained under both irradiation conditions. At the highest scavenging capacity used (approximately 10(9) s-1), about eight times more strand breaks are formed than would be predicted from homogeneous competition kinetics. The experimental data are compared with values obtained from theoretical models which are based on non-homogeneous kinetics, and include the effects of spurs and of the direct action of radiation. The comparison shows that the observed dependence of the single-strand break yield on the scavenging capacity can be quantitatively accounted for without the need of empirical adjustment of parameters using a DNA model where the macromolecules are approximated by structureless cylinders of radius Rc = 0.80 nm which on their surface react with OH radicals at a diffusion-controlled rate. The factors determining the scavenger dependence of the single-strand break yield are discussed. The increase on going to higher scavenging capacities in the apparent rate constant of the reaction of OH with DNA is rationalized in terms of the mean diffusion length of OH radicals in solution. Estimates are given for the fractions of strand breaks due to randomized OH radicals, OH radicals from spurs, and the direct radiation effect.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0955-3002
pubmed:author
pubmed:issnType
Print
pubmed:volume
59
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
677-97
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Non-homogeneous kinetics in the competition of single-stranded calf-thymus DNA and low-molecular weight scavengers for OH radicals: a comparison of experimental data and theoretical models.
pubmed:affiliation
Max-Planck-Institut für Strahlenchemie, Mülheim a.d.Ruhr, FRG.
pubmed:publicationType
Journal Article, Comparative Study