title: Novel phosphoryl derivatization method for peptide sequencing by electrospray ionization mass spectrometry.
abstract: A one-step phosphoryl derivatization method has been used in a peptide sequencing procedure for electrospray ionization tandem mass spectrometry (ESI-MS/MS). The sodiated derivatized peptides exhibit very simple dissociation patterns, in which two kinds of fragment ions, [b(n) + OH + Na]+ and [a(n) + Na]+, are formed. Since the amino acid residues are lost sequentially from the C-terminus, peptide sequences can be identified easily. The fragmentation efficiency of peptides increased as a result of the phosphorylation, and also provided peaks of useful intensity at lower m/z. A peptide with lysine at the C-terminus was derivatized and analyzed by ESI-MS/MS. Similar mass spectra, from which the sequence could be read out, were obtained. This is a novel derivatization method yielding neutral derivatives that should be suitable for peptide sequencing by LC/ESI-MS/MS.
authors.affiliation: The Key Laboratory for Bioorganic Phosphorus Chemistry of Education Ministry, Department of Chemistry, School of Life Sciences and Engineering, Tsinghua University, Beijing 100084, P.R. China.
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Peng
authors.initials: P
authors.lastname: Gong
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Yan-Mei
authors.initials: YM
authors.lastname: Li
authors.forename: Yu-Fen
authors.initials: YF
authors.lastname: Zhao
mesh_terms: D000595:Amino Acid Sequence; D010748:Phosphopeptides / Q000032:analysis / Q000737:chemistry*; D020539:Sequence Analysis, Protein / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D010748:Phosphopeptides