title: Simultaneous measurement of protein-bound 3-chlorotyrosine and homocitrulline by LC-MS/MS after hydrolysis assisted by microwave: application to the study of myeloperoxidase activity during hemodialysis.
abstract: A high degree of uremia is common in patients with end-stage renal disease and has been linked to the development of chronic inflammation and cardiovascular diseases. In conditions where transplantation is not possible, uremia can be reduced by hemodialysis although the repeated interventions have been implicated in loss of renal function, partially as a result of chronic inflammation and/or oxidative stress processes. In this context, it has been suggested that myeloperoxidase (MPO) can contribute to the oxidative stress during hemodialysis and to the cardiovascular risk. Protein damages due to MPO activity have never been assessed during hemodialysis although two of its reaction products, 3-chlorotyrosine and homocitrulline, are of interest. Indeed, the first one is a specific product of MPO activity and the formation of the second one could be catalyzed by MPO. In order to analyze these products in plasma proteins, a total hydrolysis method followed by liquid chromatography mass spectrometry analysis was developed. Different conditions of hydrolysis were tested and the optimized procedure was assessed for complete hydrolysis and artifactual chlorination. Finally, the method was used for analyzing 3-chlorotyrosine and homocitrulline in plasma proteins during a hemodialysis session in fifteen patients and data were related to measurements of MPO concentration and activity. Both increases in MPO activity and protein-bound 3-chlorotyrosine were observed, highlighting the involvement of MPO in oxidative stress during hemodialysis and further demonstrating the link between hemodialysis and cardiovascular diseases.
authors.affiliation: Laboratory of Pharmaceutical Chemistry, Faculty of Pharmacy, Université Libre de Bruxelles, Bruxelles, Belgium. cedric.delporte@ulb.ac.be
authors.forename: Cédric
authors.initials: C
authors.lastname: Delporte
authors.forename: Thierry
authors.initials: T
authors.lastname: Franck
authors.forename: Caroline
authors.initials: C
authors.lastname: Noyon
authors.forename: Damien
authors.initials: D
authors.lastname: Dufour
authors.forename: Alexandre
authors.initials: A
authors.lastname: Rousseau
authors.forename: Philippe
authors.initials: P
authors.lastname: Madhoun
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Desmet
authors.forename: Didier
authors.initials: D
authors.lastname: Serteyn
authors.forename: Martine
authors.initials: M
authors.lastname: Raes
authors.forename: Joëlle
authors.initials: J
authors.lastname: Nortier
authors.forename: Michel
authors.initials: M
authors.lastname: Vanhaeverbeek
authors.forename: Nicole
authors.initials: N
authors.lastname: Moguilevsky
authors.forename: Jean
authors.initials: J
authors.lastname: Nève
authors.forename: Luc
authors.initials: L
authors.lastname: Vanhamme
authors.forename: Pierre
authors.initials: P
authors.lastname: Van Antwerpen
authors.forename: Karim
authors.initials: K
authors.lastname: Zouaoui Boudjeltia
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D001774:Blood Chemical Analysis / Q000379:methods*; D001798:Blood Proteins / Q000378:metabolism*; D002853:Chromatography, Liquid; D002956:Citrulline / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D005260:Female; D006801:Humans; D006868:Hydrolysis; D008239:Lysine / Q000097:blood; D008297:Male; D008872:Microwaves; D008875:Middle Aged; D009195:Peroxidase / Q000097:blood / Q000378:metabolism*; D006435:Renal Dialysis; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism
chemical_list: D001798:Blood Proteins; C001352:homocitrulline; D002956:Citrulline; D014443:Tyrosine; D009195:Peroxidase; D008239:Lysine; C087259:3-chlorotyrosine