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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
19
|
| pubmed:dateCreated |
1996-12-3
|
| pubmed:abstractText |
In this paper we present methods for identifying and sequencing phosphopeptides in simple mixtures, such as HPLC fractions, at the subpicomole level by (+) ion matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-MS). Data are presented which indicate that when a reflectron time-of-flight mass spectrometer is used, MALDI can distinguish tyrosine phosphorylation from serine and threonine phosphorylation for peptides containing a single phosphate group. Phosphopeptides are identified in the (+) ion MALDI reflector spectrum by the presence of [MH-H3PO4]+ and [MH-HPO3]+ fragment ions formed by metastable decomposition. An abundant [MH-H3PO4]+ ion, accompanied by a weaker [MH-HPO3]+ ion indicates that the peptide is most likely phosphorylated on serine or threonine. In contrast, phosphotyrosine-containing peptides generally exhibit [MH-HPO3]+ fragment ions and little, if any [MH-H3PO4]+. Ambiguities do arise, most often with phosphopeptides that contain residues which readily lose water (such as unmodified serine), but these can often be resolved by recording a complete metastable fragment ion (postsource decay) spectrum. Postsource decay is shown here to be a viable technique for sequencing phosphopeptides. It can be used to distinguish between serine/ threonine and tyrosine phosphorylation and in many cases can be used to determine the exact site of phosphorylation in a peptide sequence. Nearly complete sequence coverage and phosphorylation site mapping is generally possible using approximately 300 fmol of peptide.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0003-2700
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
1
|
| pubmed:volume |
68
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
3413-21
|
| pubmed:dateRevised |
2006-11-15
|
| pubmed:meshHeading | |
| pubmed:year |
1996
|
| pubmed:articleTitle |
Phosphopeptide analysis by matrix-assisted laser desorption time-of-flight mass spectrometry.
|
| pubmed:affiliation |
Department of Physical and Structural Chemistry, SmithKline Beecham Pharmaceuticals, King of Prussia, Pennsylvania 19406, USA. Roland_S_Annan@SBPHRD.com
|
| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|