Linked Life Data

19775156

Source:http://linkedlifedata.com/resource/pubmed/id/19775156

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
42
pubmed:dateCreated
2009-10-20
pubmed:abstractText
During infection and inflammation, neutrophils and eosinophils produce hypochlorous acid, hypobromous acid, chloramines, and bromamines. These reactive halogen species preferentially oxidize methionine and thiols. It is commonly assumed that they convert methionine to methionine sulfoxide. However, iodine and organic chloramines are known to convert methionine to dehydromethionine, which is a cyclic azasulfonium salt. The potential for this reaction to occur in biologically relevant situations has so far been neglected. Therefore, we investigated the oxidation of methionine and N-terminal methionine residues by biologically relevant reactive halogen species and neutrophils. When hypochlorous acid reacted with methionine, two major products in addition to methionine sulfoxide were formed. They both had molecular masses two mass units lower than that of methionine and were identified as the diastereomers of dehydromethionine. Hypochlorous acid and chloramines converted methionine to a mixture of approximately 25% dehydromethionine and 75% methionine sulfoxide. Hypobromous acid and bromamines produced upward of 50% dehydromethionine. When methionine was present on the N-termini of peptides, reactive halogen species oxidized them to dehydromethionine with yields as high as 80%. Formylated N-terminal methionines and non-N-terminal methionine residues gave stoichiometric production of the corresponding sulfoxides only. Purified myeloperoxidase used hydrogen peroxide and chloride to catalyze the oxidation of N-terminal methionines to dehydromethionine. Neutrophils oxidized extracellular methionine to 30% dehydromethionine and 70% methionine sulfoxide. They also oxidized their intracellular methionine to dehydromethionine as well as methionine sulfoxide. We propose that reactive halogen species will produce dehydromethionine and form azasulfonium cations on the N-termini of peptides and proteins during inflammatory events.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1520-4995
pubmed:author
pubmed:issnType
Electronic
pubmed:day
27
pubmed:volume
48
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10175-82
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Oxidation of methionine to dehydromethionine by reactive halogen species generated by neutrophils.
pubmed:affiliation
Department of Pathology, University of Otago Christchurch, P.O. Box 4345, Christchurch, New Zealand.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't