Determination of Types and Binding Sites of Advanced Glycation End

Article pubs.acs.org/ac

Determination of Types and Binding Sites of Advanced Glycation End Products for Substance P Andrea F. Lopez-Clavijo,† Mark P. Barrow,† Naila Rabbani,‡ Paul J. Thornalley,‡ and Peter B. O’Connor*,† †

Warwick Centre for Analytical Science, Department of Chemistry, University of Warwick, Coventry, CV4 7AL, United Kingdom Clinical Sciences Research Laboratories, Warwick Medical School, University of Warwick, University Hospital, Coventry, CV2 2DX, United Kingdom

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S Supporting Information *

ABSTRACT: Glycation by endogenous dicarbonyl metabolites such as glyoxal is an important spontaneous post-translational (PTM) modification of peptides and proteins associated with structural and functional impairment. The aim of this study was to investigate types and site of PTM of glyoxal-derived advanced glycation end-products−in the neuropeptide substance P by ultrahigh-resolution Fourier transform ion cyclotron resonance (FTICR), mass spectrometry, and tandem mass spectrometry (MS/MS) experiments. The main site of PTM by glyoxal was the side chain guanidine moiety of the arginine residue. Binding site identification has been achieved by electron capture dissociation, double-resonance electron capture dissociation, and collisionactivated dissociation, with assignment of the modified amino acid residue with mass error