title: Quantification of tryptic peptides in quadrupole ion trap using high-mass signals derived from isotope-coded N-acetyl dipeptide tags.
abstract: Isotope-labeled N-acetyl dipeptides (Ac-Xxx-Ala) are coupled to the primary amines of tryptic peptides and then analyzed by tandem mass spectrometry. Amide bond cleavage between Xxx and Ala provides both low- and high-mass isotope-coded signals for quantification of peptides. Especially, facile cleavage at the modified lysine side chain yields very strong high-mass quantitation signals in a noise-free region. Tagging tryptic peptides with isobaric N-acetyl dipeptides is a viable strategy for accurate quantification of proteins, which can be used with most quadrupole ion trap mass spectrometers carrying the 1/3 mass cut-off problem.
authors.affiliation: Department of Chemistry, Bio-Nanotechnology Center, Pohang University of Science and Technology, Pohang, Kyungbuk, 790-784, Korea.
authors.forename: Jongcheol
authors.initials: J
authors.lastname: Seo
authors.forename: Hye-Joo
authors.initials: HJ
authors.lastname: Yoon
authors.forename: Seung Koo
authors.initials: SK
authors.lastname: Shin
mesh_terms: D000595:Amino Acid Sequence; D003903:Deuterium / Q000032:analysis / Q000737:chemistry; D004151:Dipeptides / Q000737:chemistry*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D011506:Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014357:Trypsin / Q000378:metabolism
chemical_list: D004151:Dipeptides; D010446:Peptide Fragments; D011506:Proteins; D003903:Deuterium; D014357:Trypsin