title: Quantitative analysis of complex protein mixtures using isotope-coded affinity tags.
abstract: We describe an approach for the accurate quantification and concurrent sequence identification of the individual proteins within complex mixtures. The method is based on a class of new chemical reagents termed isotope-coded affinity tags (ICATs) and tandem mass spectrometry. Using this strategy, we compared protein expression in the yeast Saccharomyces cerevisiae, using either ethanol or galactose as a carbon source. The measured differences in protein expression correlated with known yeast metabolic function under glucose-repressed conditions. The method is redundant if multiple cysteinyl residues are present, and the relative quantification is highly accurate because it is based on stable isotope dilution techniques. The ICAT approach should provide a widely applicable means to compare quantitatively global protein expression in cells and tissues.
authors.affiliation: Department of Molecular Biotechnology, University of Washington, Box 357730, Seattle WA 98195-7730, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Gygi
authors.forename: B
authors.initials: B
authors.lastname: Rist
authors.forename: S A
authors.initials: SA
authors.lastname: Gerber
authors.forename: F
authors.initials: F
authors.lastname: Turecek
authors.forename: M H
authors.initials: MH
authors.lastname: Gelb
authors.forename: R
authors.initials: R
authors.lastname: Aebersold
mesh_terms: D000345:Affinity Labels; D000595:Amino Acid Sequence; D002853:Chromatography, Liquid; D007553:Isotope Labeling; D013058:Mass Spectrometry; D011506:Proteins / Q000737:chemistry*
chemical_list: D000345:Affinity Labels; D011506:Proteins