title: Titanium dioxide coated MALDI plate for on target analysis of phosphopeptides.
abstract: Protein phosphorylation controls many cellular processes and activities. One of the major challenges in the proteomic study of phosphorylation is the enrichment of substoichiometric phosphorylated peptides from complex mixtures. Titanium dioxide (TiO2)-based chromatography is now widely applied to isolate phosphopeptides because of its efficiency and flexibility. In this study, a novel TiO2 coated matrix assisted laser desorption ionization plate is presented and tested for the purification of phosphopeptides from complex mixtures. The novel feature of this approach is the deposition of a nanostructured TiO2 film on stainless steel plates by pulsed laser deposition (PLD). By using tryptic digests of alpha-casein, beta-casein, and other nonphosphorylated proteins, the successful enrichment of phosphopeptides was possible with this novel device, called T-plate, even when working in the low fmol range, making the sample ready for mass spectrometric analysis in few minutes.
authors.affiliation: Biological Mass Spectrometry Unit, Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Via Olgettina 58, 20132 Milano, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Torta
authors.forename: Matteo
authors.initials: M
authors.lastname: Fusi
authors.forename: Carlo S
authors.initials: CS
authors.lastname: Casari
authors.forename: Carlo E
authors.initials: CE
authors.lastname: Bottani
authors.forename: Angela
authors.initials: A
authors.lastname: Bachi
mesh_terms: D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D010748:Phosphopeptides / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods; D014025:Titanium / Q000737:chemistry*
chemical_list: D010748:Phosphopeptides; C009495:titanium dioxide; D014025:Titanium