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Rapid sequencing and disulfide mapping of peptides containing disulfide bonds by using 1,5‐diaminonaphthalene as a reductive matrix
Author(s) -
Fukuyama Yuko,
Iwamoto Shinichi,
Tanaka Koichi
Publication year - 2006
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.977
Subject(s) - chemistry , disulfide bond , peptide , mass spectrometry , amino acid , peptide bond , stereochemistry , chromatography , biochemistry
MS/MS is indispensable for the amino acid sequencing of peptides. However, its use is limited for peptides containing disulfide bonds. We have applied the reducing properties of 1,5‐diaminonaphthalene (1,5‐DAN) as a MALDI matrix to amino acid sequencing and disulfide bond mapping of human urotensin II possessing one disulfide bond, and human guanylin possessing two disulfide bonds. 1,5‐DAN was used in the same manner as the usual MALDI matrices without any pre‐treatment of the peptide, and MS/MS was performed using a matrix‐assisted laser desorption/ionization quadrupole ion trap time‐of‐flight mass spectrometer (MALDI QIT TOFMS). The results demonstrated that MS/MS of the molecular ions reduced by 1,5‐DAN provided a series of significant b‐/y‐product ions. All 11 amino acid residues of urotensin II were identified using 1,5‐DAN, while only 5 out of 11 residues were identified using 2,5‐dihydroxybenzoic acid (DHB); similarly 11 out of 15 amino acid residues of guanylin were identified using 1,5‐DAN, while only three were identified using DHB. In addition, comparison of the theoretical and measured values of the mass differences between corresponding MS/MS product ions using 1,5‐DAN and DHB narrowed down the possible disulfide bond arrangement candidates. Consequently, 1,5‐DAN as a reductive matrix facilitates rapid amino acid sequencing and disulfide mapping for peptides containing disulfide bonds. Copyright © 2005 John Wiley & Sons, Ltd.