Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
14
pubmed:dateCreated
1977-8-25
pubmed:abstractText
The conditions and utility of the N-chlorosuccinimide/urea (NCS/urea) reagent for the selective cleavage of tryptophanyl peptide bonds in proteins is demonstrated with cytochrome c. At low concentrations of NCS/urea the oxidation of thioether side chains in cytochrome c is the predominant reaction. Methionyl residues are oxidized to sulfoxide and the heme-thioether bridge is partially cleaved. At 10-fold excess of NCS/urea reagent, cleavage of the tryptophanyl peptide bond is optimal at approximately 50% yield in several species of cytochrome c studied. Analytical data on isolated horse cytochrome c peptide fragments demonstrate lack of modification and cleavage at tyrosyl and histidyl residues. However, at high concentrations of NCS/urea reagent (30-fold) unexpected conversions of methionine to sulfone and cysteine to cysteic acid in intact proteins are observed. This is in contradistinction to the absence of sulfone in NCS/urea-reacted amino acid mixtures. The mechanisms of halogenation and cleavage by N-bromosuccinimide, N-iodosuccinimide, and N-chlorosuccinimide are discussed. It is porposed that the selectivity with respect to halogenation by N-chlorosuccinimide is due to the insignificant participation of molecular chlorine in the NCS/urea reaction. A mechanism of halogenation and cleavage by NCS at tryptophan is also offered.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
252
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4976-80
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
Use of N-chlorosuccinimide/urea for the selective cleavage of tryptophanyl peptide bonds in proteins. Cytochrome c.
pubmed:publicationType
Journal Article