Linked Life Data

12049792

Source:http://linkedlifedata.com/resource/pubmed/id/12049792

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-6-6
pubmed:abstractText
7,8-Dihydroneopterin and neopterin are secreted by human and primate macrophages after activation by interferon-gamma in a ratio of 2:1. 7,8-Dihydroneopterin is known to suppress radical-mediated processes, but it is also able in the presence of iron ions to generate superoxide radical anion and hydroxyl radicals from molecular oxygen. Effects of 7,8-dihydroneopterin were investigated on (met)myoglobin and (met)hemoglobin. Addition of 7,8-dihydroneopterin to heme proteins in air-saturated solution resulted in dose-dependent cleavage of the porphyrin moiety. The liberation of non-heme iron and carbon monoxide originating from the cleaved porphyrin was quantified. Both were generated at equimolar concentrations with a linear correlation coefficient of 0.9. Addition of ferrous iron significantly accelerated the pteridine-mediated cleaving of the porphyrin. However, the total yield of porphyrin cleaved was controlled by the pterin rather than by the ferrous ion concentration. 7,8-Dihydroneopterin is assumed to reduce the heme iron in intact protein molecules, thereby preparing the conditions for binding of oxygen and carbon monoxide as ligands. Beyond that, it is concluded that hydroxyl radicals might be generated via reduction of molecular oxygen to superoxide anion in the autoxidation process and dismutation to hydrogen peroxide and subsequent Fenton reaction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
1571
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
124-30
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Generation of carbon monoxide and iron from hemeproteins in the presence of 7,8-dihydroneopterin.
pubmed:affiliation
Institute for Medical Chemistry and Pregl Laboratory, University Graz, Harrachgasse 21/II, Austria. renate.horejsi@kfunigraz.ac.at
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't