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Updated: Aug 8, 2026

Enhanced Sample Multiplexing of Tissues Using Combined Precursor Isotopic Labeling and Isobaric Tagging (cPILOT)
Published on: May 1, 2017
A novel multifunctional labeling reagent for enhanced protein characterization with mass spectrometry
E C Peters1, D M Horn, D C Tully
1The Genomics Institute of the Novartis Research Foundation, 3115 Merryfield Row, San Diego, CA 92121, USA. peters@gnf.org
Abstract:
Individual peptides with lysine at the C-terminus as well as protein tryptic digests were reacted with 2-methoxy-4,5-dihydro-1H-imidazole, converting lysine residues to their 4,5-dihydro-1H-imidazol-2-yl derivatives. The mass spectra of derivatized digests exhibit a greater number of more intense features than their underivatized counterparts, thus increasing the information obtained in peptide mapping experiments. Additionally, MS/MS spectra of the derivatized peptides are greatly simplified in comparison to their native species, yielding primarily an easily interpretable series of y-ions. Finally, this novel label also enables differential quantitation studies, as a stable isotopic form containing four deuterium atoms can readily be produced.
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