Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-12-12
pubmed:abstractText
In this study, a solution isoelectric focusing apparatus was modified and built into a two-dimensional separation method for peptides. Newly commercialized isoelectric membranes, which carry immobilized ampholytes, were integrated to establish the pH boundaries in this apparatus. High-performance liquid chromatography was employed as the second dimension, interfaced with mass spectrometry. An insoluble nuclear protein fraction was used to evaluate and optimize this method. This two-dimensional separation method dramatically improves peptide detection and identification compared with a single dimension LC-MS analysis. Off-line reversed-phase HPLC was used to ascertain reproducibility. The two-dimensional separation method was combined with (18)O labeling for comparative analysis of protein expression in two cell lines. Separation of peptides by solution isoelectric focusing (sIEF) offers the advantage that it can be accomplished after the (18)O labels are introduced. The labeled peptides can be mixed with unlabeled ones before fractionation by sIEF. The relative abundances of nuclear proteins from a drug resistant MCF-7 cancer cell line were compared to those from the drug susceptible parent cell line using this combined strategy. The abundances of several heterogeneous nuclear ribonucleoproteins were found to be increased in the mitoxantrone-resistant line.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1535-3893
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2126-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:articleTitle
Solution isoelectric focusing for peptide analysis: comparative investigation of an insoluble nuclear protein fraction.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural