Linked Life Data

7871151

Source:http://linkedlifedata.com/resource/pubmed/id/7871151

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-3-30
pubmed:abstractText
Escherichia coli K12 bacteria strains AB1157 (repair-deficient wild-type, uvrA+ recA+), AB1886 (urvA-), AB2463 (recA-) and AB2480 (urvA- recA-) were exposed to 254 nm germicidal UV and 216 or 193 nm laser radiation. The mean lethal incident dose (D37) for AB1157 does not change significantly with wavelength, whereas it increases for the other strains on going from lambda irr = 254 to 193 nm, e.g. eightfold for AB2480. Quantum yields for inactivation, due to light absorbed by the chromosomal DNA, have been estimated from the D37 values. The large differences in D37 between uvrA+ and uvrA- strains indicate a significant contribution of pyrimidine dimers and (6-4) photoproducts to photodamage of DNA in the cells. The formation of dimers even with lambda irr = 193 nm is supported by the result that the photoreactivable sector is larger than 63%. Inactivation of E. coli upon irradiation at 193 and 216 nm is therefore due to damage to intracellular DNA rather than to membrane or protein damage as is the case for mammalian cells. The ratio of the lethal doses for AB1157 vs AB2480 is approximately 900 with lambda irr = 254 nm, but only 160 with lambda irr = 193 nm. We propose that this is due to the better repair of photodimers and (6-4) photoproducts than of damage induced by photoionization via upper excited states. Irradiation at 193 nm inactivates AB1157 mainly by damage due to photoionization and AB2480 by damage due to photodimers in the chromosomal DNA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0033-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
141
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
244-51
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Ultraviolet (193, 216 and 254 nm) photoinactivation of Escherichia coli strains with different repair deficiencies.
pubmed:affiliation
Max-Planck-Institut für Strahlenchemie, Mülheim an der Ruhr, Germany.
pubmed:publicationType
Journal Article