title: Quantitative analysis of glycated proteins.
abstract: The proposed protocol presents a comprehensive approach for large-scale qualitative and quantitative analysis of glycated proteins (GP) in complex biological samples including biological fluids and cell lysates such as plasma and red blood cells. The method, named glycation isotopic labeling (GIL), is based on the differential labeling of proteins with isotopic [(13)C6]-glucose, which supports quantitation of the resulting glycated peptides after enzymatic digestion with endoproteinase Glu-C. The key principle of the GIL approach is the detection of doublet signals for each glycated peptide in MS precursor scanning (glycated peptide with in vivo [(12)C6]- and in vitro [(13)C6]-glucose). The mass shift of the doublet signals is +6, +3 or +2 Da depending on the peptide charge state and the number of glycation sites. The intensity ratio between doublet signals generates quantitative information of glycated proteins that can be related to the glycemic state of the studied samples. Tandem mass spectrometry with high-energy collisional dissociation (HCD-MS2) and data-dependent methods with collision-induced dissociation (CID-MS3 neutral loss scan) are used for qualitative analysis.
authors.affiliation: Translational Biomarker Group (TBG), Department of Human Protein Sciences, University Medical Centre, University of Geneva , 1211 Geneva 4, Switzerland.
authors.forename: Feliciano
authors.initials: F
authors.lastname: Priego-Capote
authors.forename: María
authors.initials: M
authors.lastname: Ramírez-Boo
authors.forename: Francesco
authors.initials: F
authors.lastname: Finamore
authors.forename: Florent
authors.initials: F
authors.lastname: Gluck
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Sanchez
mesh_terms: D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D005947:Glucose / Q000737:chemistry*; D008969:Molecular Sequence Data; D011506:Proteins / Q000032:analysis* / Q000737:chemistry; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D011506:Proteins; D005947:Glucose