Rapid sequencing and disulfide mapping of peptides containing disulfide bonds by using 1,5-diaminonaphthalene as a reductive matrix
Article first published online: 29 DEC 2005
Copyright © 2005 John Wiley & Sons, Ltd.
Journal of Mass Spectrometry
Volume 41, Issue 2, pages 191–201, February 2006
How to Cite
Fukuyama, Y., Iwamoto, S. and Tanaka, K. (2006), Rapid sequencing and disulfide mapping of peptides containing disulfide bonds by using 1,5-diaminonaphthalene as a reductive matrix. J. Mass Spectrom., 41: 191–201. doi: 10.1002/jms.977
- Issue published online: 31 JAN 2006
- Article first published online: 29 DEC 2005
- Manuscript Accepted: 29 OCT 2005
- Manuscript Received: 13 SEP 2005
- 1,5-diaminonaphthalene (1,5-DAN);
- disulfide bonds;
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.