Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-3-1
pubmed:abstractText
Cpe(fat/fat) mice have a point mutation in the coding region of the carboxypeptidase E gene that renders the enzyme inactive. As a result, these mice have reduced levels of several neuropeptides and greatly increased levels of the peptide processing intermediates that contain C-terminal basic residues. However, previous studies examined a relatively small number of neuropeptides. In the present study, we used a quantitative peptidomics approach with stable isotopic labels to examine the levels of pituitary peptides in Cpe(fat/fat) mice relative to wild-type mice. Pituitary extracts from mutant and wild type mice were labeled with the stable isotopic label [3-(2,5-dioxopyrrolidin-1-yloxycarbonyl)propyl]trimethylammonium chloride containing nine atoms of hydrogen or deuterium. Then, the two samples were pooled and analyzed by liquid chromatography/mass spectrometry (LC/MS). The relative abundance of peptides was determined from a comparison of the intensities of the heavy and light peaks. Altogether, 72 peptides were detected in the Cpe(fat/fat) and/or wild-type mouse pituitary extracts of which 53 were identified by MS/MS sequencing. Several peptides identified in this analysis represent previously undescribed post-translational processing products of known pituitary prohormones. Of the 72 peptides detected in pituitary, 17 were detected only in the Cpe(fat/fat) mouse extracts; these represent peptide processing intermediates containing C-terminal basic residues. The peptides common to both Cpe(fat/fat) and wild-type mice were generally present at 2-5-fold lower levels in the Cpe(fat/fat) mouse pituitary extracts, although some peptides were present at equal levels and one peptide (acetyl beta-endorphin 1-31) was increased approximately 7-fold in the Cpe(fat/fat) pituitary extracts. In contrast, acetyl beta-endorphin 1-26 was present at approximately 10-fold lower levels in the Cpe(fat/fat) pituitary, compared with wild-type mice. The finding that many peptides are substantially decreased in Cpe(fat/fat) pituitary is consistent with the broad role for carboxypeptidase E in the biosynthesis of numerous neuropeptides.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1076-5174
pubmed:author
pubmed:copyrightInfo
Copyright 2005 John Wiley & Sons, Ltd.
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
227-37
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Relative quantitation of peptides in wild-type and Cpe(fat/fat) mouse pituitary using stable isotopic tags and mass spectrometry.
pubmed:affiliation
Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.