Linked Life Data

7775006

Source:http://linkedlifedata.com/resource/pubmed/id/7775006

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-7-11
pubmed:abstractText
An evaluation was made of the two methods most commonly used for phosphorylation of hydroxyamino acids in peptides, i.e. the tetrazole-catalysed phosphitylation by di-tert-butyl-N,N-diethylphosphoramidite followed by oxidation and the phosphorylation by dibenzylphosphochloridate. As model system the sequence GGXA (X = S, T, Y) was used which represents a random-coil sequence avoiding the influence on the reaction kinetics of secondary structure formation. In the case of serine- and threonine-containing peptides, both synthetic methods gave comparable yields of the desired phosphopeptides. The phosphorylation of tyrosine was achieved more favorably via the phosphoramidite method. However, phosphotyrosine peptides are most easily obtained by peptide synthesis using Fmoc-Tyr(PO3Me2)OH as building block. The dibenzylphosphochloridate method yields the expected phosphopeptides as the only peptide derivative and in addition, a great number of unidentified by-products which can be removed by ion-exchange chromatography. The phosphoramidite method consistently resulted in three peptide derivatives, i.e. the desired phosphopeptide, the phosphitylated peptide and a bridged derivative with two GGXA fragments linked through a phosphodiester bridge. The derivatives were characterised by RP and ion-exchange chromatography, 31P- and 1H-NMR spectroscopy, and ion-spray and electrospray mass spectrometry. Interestingly, even these mild ionisation techniques resulted in partial fragmentation. The observed fragmentation pathways seem to be a diagnostic tool for the identification of phosphorylation sites in peptides. Both the phosphorylated serine and threonine peptide lost phosphoric acid (98 mass units), the tyrosine peptide lost phenyl phosphate (174 mass units).(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0367-8377
pubmed:author
pubmed:issnType
Print
pubmed:volume
45
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
26-34
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Chemical phosphorylation of the peptides GGXA (X = S, T, Y): an evaluation of different chemical approaches.
pubmed:affiliation
Department of Biochemistry, University of Saarland, Saarbrücken, Germany.
pubmed:publicationType
Journal Article, Comparative Study