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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2002-6-19
pubmed:abstractText
We present measurements of low-energy (<18 eV) electron-stimulated desorption of anions from acetamide (CH(3)CONH(2)) and dimethyl disulfide [DMDS: (CH(3)S)(2)] films. Electron irradiation of physisorbed CH(3)CONH(2) produces H(-), CH(3)(-) and O(-) anions, whereas the H(-), CH(2)(-), CH(3)(-), S(-), SH(-) and SCH(3)(-) anions are observed to desorb from the DMDS film. Below 12 eV, the dependence of the anion yields on the incident electron energy exhibits structures that indicate that a resonant process (i.e. dissociative electron attachment) is responsible for molecular fragmentation. Within the range of 1-18 eV, it is found that (1.7 and 1.4) x 10(7) H(-) ions/incident electron and (7.8 x 10(-11) and 4.3 x 10(-8)) of the other ions/incident electron are desorbed from acetamide and DMDS films, respectively. These results suggest that, within proteins, the disulfide bond is more sensitive to low-energy electron attack than the peptide bond. In biological cells, some proteins interact closely with nucleic acid. Therefore, the observed fragments, when produced from secondary low-energy electrons generated by high-energy radiation, not only may denature proteins, but may also induce reactions with the nearby nucleic acid and damage DNA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0033-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
158
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23-31
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Alteration of protein structure induced by low-energy (<18 eV) electrons. I. The peptide and disulfide bridges.
pubmed:affiliation
Group of the Canadian Institutes of Health Research in the Radiation Sciences, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, Québec, Canada, J1H 5N4.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't