Isobaric Peptide Termini Labeling for MS/MS-Based Quantitative Proteomics

Koehler, C.J., Strozynski, M., Kozielski, F., Treumann, A. and Thiede, B. (2009) Isobaric Peptide Termini Labeling for MS/MS-Based Quantitative Proteomics. Journal of Proteome Research, 8(9), pp. 4333-4341. (doi: 10.1021/pr900425n)

Abstract

Since its introduction, isobaric peptide labeling has played an important role in relative quantitative comparisons of proteomes. This paper describes isobaric peptide termini labeling (IPTL), a novel approach for the identification and quantification of two differentially labeled states using MS/MS spectra. After endoproteinase Lys-C digestion, peptides were labeled at C-terminal lysine residues with either 2-methoxy-4,5-dihydro-1H-imidazole (MDHI) or with tetradeuterated MDHI-d(4). Subsequently, their N-termini were derivatized either with tetradeuterated succinic anhydride (SA-d(4)) or with SA. The mixed isotopic labeling results in isobaric masses and provided several quantification data points per peptide. The suitability of this approach is demonstrated with MS and MS/MS analyses of Lys-C digests of standard proteins. A conceptually simple quantification strategy with a dynamic range of 25 is achieved through the use of Mascot score ratios. The utility of IPTL for the analysis of proteomes was verified by comparing the well-characterized effect of the antimitotic inhibitor S-Trityl-L-Cysteine (STLC) on HeLa cells that were treated for either 24 or 48 h with the inhibitor. Many apoptosis-linked proteins were identified as being differentially regulated, confirming the suitability of IPTL for the analysis of complex proteomes.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Kozielski, Professor Frank
• Authors: Koehler, C.J., Strozynski, M., Kozielski, F., Treumann, A., and Thiede, B.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Journal of Proteome Research
• ISSN: 1535-3893