Novel phosphoryl derivatization method for peptide sequencing by electrospray ionization mass spectrometry.
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.
Chen
Jing
J
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.
Chen
Yi
Y
Gong
Peng
P
Jiang
Yang
Y
Li
Yan-Mei
YM
Zhao
Yu-Fen
YF
D000595:Amino Acid Sequence; D010748:Phosphopeptides / Q000032:analysis / Q000737:chemistry*; D020539:Sequence Analysis, Protein / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D010748:Phosphopeptides