Details

Autor(en) / Beteiligte

• Singh, Sasha
• Springer, Michael
• Steen, Judith
• Kirschner, Marc W
• Steen, Hanno

Titel

FLEXIQuant: A Novel Tool for the Absolute Quantification of Proteins, and the Simultaneous Identification and Quantification of Potentially Modified Peptides

Ist Teil von

• Journal of proteome research, 2009-05, Vol.8 (5), p.2201-2210

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2009

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Measurements of protein abundance and quantitative assessment of multiple post-translational modifications (PTMs) within a single protein are increasingly used to understand the control of protein activity, particularly in metazoan cells. General methods of wide applicability and precision/accuracy for quantitative estimation of protein post-translational regulation are lacking. Protein mass spectrometry has evolved from a high-throughput qualitative technique to a potentially general quantitative tool, but there are still serious limitations in dynamic range and coverage. To address some of these limitations, we introduce a novel MS-based quantitative strategy, FLEXIQuant, (Full-Length Expressed Stable Isotope-labeled Proteins for Quantification), which can track changes in relative peptide abundances as a function of PTM, and determine absolute quantity of a protein from its lysate. We examined two subunits of the anaphase-promoting complex, CDC27 and APC5, as a test of our ability to monitor quantitatively, the PTM status of several peptides over time. We find evidence of differential regulation at different sites, a phenomenon we believe will be very widespread. FLEXIQuant proved itself to be capable of serving as a general quantitative tool.