Trace Labeling of Proteins with Stable Isotopes To Identify Fragments in Complex Mixtures
| Autor: | Richard G Phelps, A Neil Turner, Juan Zou |
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| Rok vydání: | 2004 |
| Předmět: |
Ions
chemistry.chemical_classification Carbon Isotopes Chromatography Isotope Chemistry Stable isotope ratio Carbon-13 Proteins Peptide Mass spectrometry Sensitivity and Specificity Analytical Chemistry Automation Matrix-assisted laser desorption/ionization Isotopes of carbon Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization Mass spectrum Trypsin Peptides |
| Zdroj: | Analytical Chemistry. 76:1445-1452 |
| ISSN: | 1520-6882 0003-2700 |
| DOI: | 10.1021/ac035160i |
| Popis: | We describe a novel nonradioactive protein-labeling technique that permits mass spectrometric identification of fragments of labeled proteins. Proteins are labeled by modulating their content of carbon-13 and labeled fragments identified from the distinctive isotope pattern observed on MALDI-TOF mass spectrometry. We show that carbon-13 enrichment to just 2.3% of total carbon (about twice the natural abundance of 1.1%) is sufficient for all fragments to be distinguishable from fragments of natural carbon-13-content proteins. Distinguishing labeled fragments is easily accomplished by visual inspection of spectra, but importantly, we show that labeled fragments can also be identified by computer analysis of spectra using novel parameters we have derived. The technique is demonstrated for identification of fragments of carbon-13-enriched glutathione transferase within a complex mixture of unlabeled peptides by visual and computer analysis of MALDI-TOF mass spectra, but it could be developed to mass spectrometrically identify and characterize fragments of labeled proteins recovered from biological systems. |
| Databáze: | OpenAIRE |
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