HIGH RESOLUTION MASS SPECTROMETRIC STRATEGIES FOR DETECTION OF PROTEINS AND PEPTIDES COVALENTLY MODIFIED BY ELECTROPHILIC XENOBIOTICS AND ENDOGENOUS INTERMEDIATES

Non enzymatic protein covalent modifications are involved in the toxic effects induced by electrophilic xenobiotics as well as by endogenous cytotoxic oxidation by-products. Aim of my Ph.D work was to set-up MS methods for the identification, characterization and quantification of non-enzymatic covalently modified proteins and peptides in biological matrices. To reach this goal both tandem MS and high resolution approaches were employed due to the wealth of structural and molecular information that these techniques can provide. As a first step the MS methods were applied for understanding in both in vitro and ex vivo conditions the mechanism of protein haptenation induced by amoxicillin (AX). The MS approach was then focused to study in ex vivo condition the covalent reaction between histidine dipeptides, such as carnosine, and toxic endogenous intermediates like reactive carbonyl species (RCS). .