Linked Life Data

16970346

Source:http://linkedlifedata.com/resource/pubmed/id/16970346

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
2006-9-14
pubmed:abstractText
We find that peptides containing -Asn-Gly- sequences typically show approximately 70-80% degree of deamidation after standard overnight (approximately 12 h) tryptic digestion at 37 degrees C. This emphasizes the need for more detailed information about the deamidation reaction in -Asn-Gly- sequences, in which two deamidated species are produced, one containing an aspartic acid (-Asp-Gly-) residue and the other containing an isoaspartic acid (-betaAsp-Gly-) residue. For the peptide SLNGEWR (54-60 beta-galactosidase, E. coli), all three components of the reaction mixture were separated by HPLC on C18 300-A sorbent, with trifluoroacetic acid as an ion-pairing modifier. Their intensity ratios suggested the elution order -betaAsp-/-Asn-/-Asp-, which was subsequently confirmed by MALDI MS and MS/MS analysis. The kinetics of the deamidation was studied in detail for the synthetic SLNGEWR parent using RP HPLC with UV detection. The half-life of this peptide was found to be approximately 8 h under digestion conditions. Analysis of a large pool of peptide retention data shows that the -betaAsp-/-Asn-/ -Asp- retention order is normally observed under the above conditions, especially if the original -NG- sequence is surrounded by hydrophobic amino acids. However, changing chromatographic conditions to 100-A pore size sorbents, or using formic acid as a modifier, increases the retention time of -betaAsp- relative to the -Asn-/-Asp- pair, so the order can sometimes be different.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0003-2700
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
78
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6645-50
pubmed:dateRevised
2007-12-3
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Deamidation of -Asn-Gly- sequences during sample preparation for proteomics: Consequences for MALDI and HPLC-MALDI analysis.
pubmed:affiliation
Manitoba Centre for Proteomics and Systems Biology, University of Manitoba 799 JBRC, 715 McDermot Avenue, Winnipeg, MB, R3E 3P4, Canada. krokhino@cc.umanitoba.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural