Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1990-10-23
pubmed:abstractText
The sulfhydryl enzyme malate synthase was inactivated by X-irradiation in air-saturated aqueous solution, in the absence or presence of a variety of additives (thiols, antioxienzymes, typical radical scavengers, inorganic salts, buffer components, substrates, products, analogues). Radiation-induced changes of enzymic activity were registered immediately after stop of irradiation and in the post-irradiation period. Repair experiments were initiated by post-irradiation addition of dithiothreitol. Additionally, post-irradiation inactivation was modulated by some further additives. Probing the extent of primary and post-irradiation inactivation and repair was accomplished effectively by screening experiments on the microlevel, and by derivation of normalized efficiency parameters which allowed quick comparisons of the various additives with respect to their protective and repair-promotive efficiencies. Correlations between the efficiency parameters were studied by means of binary and ternary diagrams. Most of the substances added before irradiation were found to protect the enzyme against primary and post-irradiation inactivation and to increase the reparability of the enzyme by dithiothreitol, the extent of the effects depending on the nature (and concentration) of the additives used. Our results indicate that both specific protection (by substrates, products, analogues, and by sulfhydryl agents) and scavenging are responsible for the radioprotective efficiencies of the additives.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0939-5075
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
645-54
pubmed:dateRevised
2009-11-4
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
X-ray induced inactivation of the sulfhydryl enzyme malate synthase in the presence of various additives. Probing the extent of primary and post-irradiation inactivation and repair by rapid screening on the microlevel.
pubmed:affiliation
Institut für Biophysik und Physikalische Biochemie, Universität Regensburg, Bundesrepublik Deutschland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't