Peptide mass mapping constrained with stable isotope-tagged peptides for identification of protein mixtures

T. C. Hunter, L. Yang, H. Zhu, V. Majidi, E. Morton Bradbury, X. Chen

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


Through proteolysis and peptide mass determination using mass spectrometry, a peptide mass map (PMM) can be generated for protein identification. However, insufficient peptide mass accuracy and protein sequence coverage limit the potential of the PMM approach for high-throughput, large-scale analysis of proteins. In our novel approach, nonlabile protons in particular amino acid residues were replaced with deuteriums to mass-tag proteins of the S. cerevisiae proteome in a sequence-specific manner. The resulting mass-tagged proteolytic peptides with characteristic mass-split patterns can be identified in the data search using constraints of both amino acid composition and mass-to-charge ratio. More importantly, the mass-tagged peptides can further act as internal calibrants with high confidence in a PMM to identify the parent proteins at modest mass accuracy and low sequence coverage. As a result, the specificity and accuracy of a PMM was greatly enhanced without the need for peptide sequencing or instrumental improvements to obtain increased mass accuracy. The power of PMM has been extended to the unambiguous identification of multiple proteins in a 1D SDS gel band including the identification of a membrane protein.

Original languageEnglish
Pages (from-to)4891-4902
Number of pages12
JournalAnalytical Chemistry
Issue number20
StatePublished - Oct 15 2001

ASJC Scopus subject areas

  • Analytical Chemistry


Dive into the research topics of 'Peptide mass mapping constrained with stable isotope-tagged peptides for identification of protein mixtures'. Together they form a unique fingerprint.

Cite this