title: Biomarkers probed in saliva by surface plasmon resonance imaging coupled to matrix-assisted laser desorption/ionization mass spectrometry in array format.
abstract: Detection of protein biomarkers is of major interest in proteomics. This work reports the analysis of protein biomarkers directly from a biological fluid, human saliva, by surface plasmon resonance imaging coupled to mass spectrometry (SPRi-MS), using a functionalized biochip in an array format enabling multiplex SPR-MS analysis. The SPR biochip presented a gold surface functionalized by a self-assembled monolayer of short poly(ethylene oxide) chains carrying an N-hydroxysuccinimide end-group for the immobilization of antibodies. The experiments were accomplished without any sample pre-purification or spiking with the targeted biomarkers. SPRi monitoring of the interactions, immune capture from the biochip surface, and finally on-chip matrix-assisted laser desorption/ionization-MS structural identification of two protein biomarkers, salivary α-amylase and lysozyme, were successively achieved directly from saliva at the femtomole level. For lysozyme, the on-chip MS identification was completed by a proteomic analysis based on an on-chip proteolysis procedure and a peptide mass fingerprint.
authors.affiliation: CNRS, UMR8587, Laboratoire Analyse et Modélisation pour la Biologie et l'Environnement, 91025, Evry, France.
authors.forename: Johana
authors.initials: J
authors.lastname: Musso
authors.forename: William
authors.initials: W
authors.lastname: Buchmann
authors.forename: Florence
authors.initials: F
authors.lastname: Gonnet
authors.forename: Nathalie
authors.initials: N
authors.lastname: Jarroux
authors.forename: Sophie
authors.initials: S
authors.lastname: Bellon
authors.forename: Chiraz
authors.initials: C
authors.lastname: Frydman
authors.forename: Didier-Luc
authors.initials: DL
authors.lastname: Brunet
authors.forename: Regis
authors.initials: R
authors.lastname: Daniel
mesh_terms: D015415:Biomarkers / Q000737:chemistry*; D006801:Humans; D009113:Muramidase / Q000737:chemistry; D010449:Peptide Mapping; D012463:Saliva / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000295:instrumentation / Q000379:methods*; D000516:alpha-Amylases / Q000737:chemistry
chemical_list: D015415:Biomarkers; D000516:alpha-Amylases; D009113:Muramidase