Linked Life Data

2851201

Source:http://linkedlifedata.com/resource/pubmed/id/2851201

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3-4
pubmed:dateCreated
1989-3-2
pubmed:abstractText
4-Hydroxyestradiol bearing a 3H label specifically at C-2 was prepared chemically and incubated with male rat liver microsomes or mushroom tyrosinase. A very high proportion (80-90%) of the 3H was displaced from the labeled steroid when either glutathione or N-acetylcysteine was present, and tyrosinase was shown not to require NADPH as cofactor for this reaction. In either case, only negligible amounts (less than 3%) of the 3H radioactivity were found associated with water-soluble adducts in contrast to 3H-labeled 2-hydroxyestradiol, which gave rise to about 25% of such products. The effect of ascorbic acid on the microsomal reaction with regiospecifically labeled estradiol, 2-hydroxyestradiol, and 4-hydroxyestradiol was also investigated, and the results are discussed in terms of the reactivity at different carbon atoms in ring A of the catechol estrogens. All the evidence points to conjugation of 4-hydroxyestradiol with glutathione or N-acetylcysteine at C-2 but not C-1 of this highly reactive catechol estrogen. Measuring the displacement of 3H as 3H2O from specific positions in the steroid ring provides a useful and sensitive method to assess the formation of adducts in cases where their isolation and characterization is particularly difficult.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0039-128X
pubmed:author
pubmed:issnType
Print
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
395-409
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
4-Hydroxyestradiol is conjugated with thiols primarily at C-2: evidence from regiospecific displacement of tritium by rat liver microsomes or tyrosinase.
pubmed:affiliation
Department of Biochemistry, Queen's University, Kingston, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't