Linked Life Data

2510407

Source:http://linkedlifedata.com/resource/pubmed/id/2510407

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1989-12-21
pubmed:abstractText
1. The ability of haem to catalyse the reductive activation of carbon tetrachloride (CCl4) in vitro has been investigated under anaerobic conditions, using methaemalbumin (MHA) and either sodium dithionite or NADPH together with NADPH-cytochrome P-450 reductase (EC 1.6.2.4) as the reducing agents. 2. In the non-enzymic system protohaem and other non-physiological haem analogues underwent rapid and extensive CCl4-dependent degradation, due to irreversible modification of their porphyrin tetrapyrrolic structure. 3. This mechanism of non-enzymic activation of CCl4 by protohaem mimics that catalyzed by cytochrome P-450 in that it requires a free, reduced haem iron and electron donation and it is largely prevented by carbon monoxide. 4. H.p.l.c. analysis of 14C-haem after anaerobic incubation with CCl4 and sodium dithionite gave radioactive products which eluted before and after haem, and exhibited significantly lower absorbance at 400 nm compared with authentic haem. When the products of CCl4-dependent haem degradation were methylated and applied to silica for t.l.c., two non-fluorescent pigments were isolated, purified and partially characterized. 5. On incubation of haem with 14CCl4 and sodium dithionite a 1:1 stoichiometry could be calculated for haem loss and 14CCl4-derived adduct formation, indicating that, as with microsomes, the loss of haem may be the result of a typical 'suicidal' inactivation reaction where the same haem moiety is both the site of CCl4 activation and the target of CCl4 reactive metabolites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0049-8254
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1023-35
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
The degradation of haem by carbon tetrachloride: metabolic activation requires a free axial coordination site on the haem iron and electron donation.
pubmed:affiliation
Biochemical Pharmacology Section, Toxicology Unit, Medical Research Council Laboratories, Surrey, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't