title: Phosphopeptide enrichment with stable spatial coordination on a titanium dioxide coated glass slide.
abstract: Recent advances in phosphoproteomics have established powerful tools to analyze phosphorylation events. However, their spatial localization is lost due to sample homogenization procedures prior to the analysis. Imaging mass spectrometry (IMS) has emerged as a method to visualize the spatial distribution of molecules in tissue samples, but its application is still limited to relatively abundant molecules. Due to low phosphorylation stoichiometry, direct detection and imaging of protein phosphorylation by MS has not been achieved yet. Therefore we have developed a novel phosphopeptide enrichment strategy as a potential tool for in situ affinity imaging MS (AIMS). A specific type of titanium dioxide (TiO2)-coated glass slides was designed and validated with casein tryptic digests for their ability to selectively retain phosphopeptides while maintaining their spatial coordination.
authors.affiliation: Turku Centre for Biotechnology, University of Turku and Abo Akademi University, FIN-20521 Turku, Finland.
authors.forename: Susumu Y
authors.initials: SY
authors.lastname: Imanishi
authors.forename: Petri
authors.initials: P
authors.lastname: Kouvonen
authors.forename: Jan-Henrik
authors.initials: JH
authors.lastname: Smått
authors.forename: Mikko
authors.initials: M
authors.lastname: Heikkilä
authors.forename: Emilia
authors.initials: E
authors.lastname: Peuhu
authors.forename: Andrey
authors.initials: A
authors.lastname: Mikhailov
authors.forename: Mikko
authors.initials: M
authors.lastname: Ritala
authors.forename: Mika
authors.initials: M
authors.lastname: Lindén
authors.forename: Garry L
authors.initials: GL
authors.lastname: Corthals
authors.forename: John E
authors.initials: JE
authors.lastname: Eriksson
mesh_terms: D002364:Caseins / Q000737:chemistry / Q000378:metabolism; D005898:Glass / Q000737:chemistry*; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D010748:Phosphopeptides / Q000737:chemistry* / Q000378:metabolism; D040901:Proteomics; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014025:Titanium / Q000737:chemistry*; D014357:Trypsin / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D002364:Caseins; D010446:Peptide Fragments; D010748:Phosphopeptides; C009495:titanium dioxide; D014025:Titanium; D014357:Trypsin