title: Reactive landing of gas-phase ions as a tool for the fabrication of metal oxide surfaces for in situ phosphopeptide enrichment.
abstract: Zirconium, titanium, and hafnium oxide-coated stainless steel surfaces are fabricated by reactive landing of gas-phase ions produced by electrospray ionization of group IVB metal alkoxides. The surfaces are used for in situ enrichment of phosphopeptides before analysis by matrix-assisted laser desorption ionization (MALDI) mass spectrometry. To evaluate this method we characterized ZrO(2) (zirconia) surfaces by (1) comparison with the other group IVB metal oxides of TiO(2) (titania) and HfO(2) (hafnia), (2) morphological characterization by SEM image analysis, and (3) dependence of phosphopeptide enrichment on the metal oxide layer thickness. Furthermore, we evaluated the necessity of the reactive landing process for the construction of useful metal oxide surfaces by preparing surfaces by electrospray deposition of Zr, Ti, and Hf alkoxides directly onto polished metal surfaces at atmospheric pressure. Although all three metal oxide surfaces evaluated were capable of phosphopeptide enrichment from complex peptide mixtures, zirconia performed better than hafnia or titania as a result of morphological characteristics illustrated by the SEM analysis. Metal oxide coatings that were fabricated by atmospheric pressure deposition were still capable of in situ phosphopeptide enrichment, although with inferior efficiency and surface durability. We show that zirconia surfaces prepared by reactive landing of gas-phase ions can be a useful tool for high throughput screening of novel phosphorylation sites and quantitation of phosphorylation kinetics.
authors.affiliation: Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
authors.forename: Grady R
authors.initials: GR
authors.lastname: Blacken
authors.forename: Michael
authors.initials: M
authors.lastname: Volný
authors.forename: Matthew
authors.initials: M
authors.lastname: Diener
authors.forename: Karl E
authors.initials: KE
authors.lastname: Jackson
authors.forename: Pratistha
authors.initials: P
authors.lastname: Ranjitkar
authors.forename: Dustin J
authors.initials: DJ
authors.lastname: Maly
authors.forename: Frantisek
authors.initials: F
authors.lastname: Turecek
mesh_terms: D000818:Animals; D001274:Atmospheric Pressure; D002364:Caseins / Q000737:chemistry / Q000378:metabolism; D002645:Chickens; D004867:Equipment Design; D004926:Escherichia coli / Q000235:genetics; D006195:Hafnium / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D010748:Phosphopeptides / Q000737:chemistry* / Q000378:metabolism; D010766:Phosphorylation; D040901:Proteomics / Q000379:methods; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000737:chemistry / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013193:Stainless Steel / Q000737:chemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D002364:Caseins; D010087:Oxides; D010748:Phosphopeptides; D013193:Stainless Steel; C009495:titanium dioxide; D012710:Serum Albumin, Bovine; D015040:Zirconium; D014025:Titanium; D016392:Proto-Oncogene Proteins pp60(c-src); C028541:zirconium oxide; D006195:Hafnium