title: Zirconium phosphonate-modified porous silicon for highly specific capture of phosphopeptides and MALDI-TOF MS analysis.
abstract: Phosphorylation is one of the most important post-translational modifications of proteins, which modulates a wide range of biological functions and activity of proteins. The analysis of phosphopeptides is still one of the most challenging tasks in proteomics research by mass spectrometry. In this study, a novel phosphopeptide enrichment approach based on the strong interaction of zirconium phosphonate (ZrP) modified surface with phosphopeptides has been developed. ZrP modified porous silicon (ZrP-pSi) wafer was prepared to specifically capture the phosphopeptides from complex peptide mixtures, and then the captured phosphopeptides were analyzed by MALDI-TOF MS by directly placing the wafer on a MALDI target. The phosphopeptide enrichment and MALDI analysis were both performed on the ZrP-pSi wafer which significantly reduced the sample loss and simplified the analytical procedures. The prepared ZrP-pSi wafer has been successfully applied for the enrichment of phosphopeptides from the tryptic digest of standard phosphoproteins beta-casein and alpha-casein. The excellent selectivity of this approach was demonstrated by analyzing phosphopeptides in the digest mixture of beta-casein and bovine serum albumin with molar ratio of 1:100. High detection sensitivity has been achieved for the analysis of the phosphopeptides from tryptic digestion of 2 fmol beta-casein on the ZrP-pSi surface.
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
authors.forename: Houjiang
authors.initials: H
authors.lastname: Zhou
authors.forename: Songyun
authors.initials: S
authors.lastname: Xu
authors.forename: Mingliang
authors.initials: M
authors.lastname: Ye
authors.forename: Shun
authors.initials: S
authors.lastname: Feng
authors.forename: Chensong
authors.initials: C
authors.lastname: Pan
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Jiang
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Guanghui
authors.initials: G
authors.lastname: Han
authors.forename: Yu
authors.initials: Y
authors.lastname: Fu
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D000595:Amino Acid Sequence; D008969:Molecular Sequence Data; D063065:Organophosphonates / Q000737:chemistry; D010748:Phosphopeptides / Q000032:analysis* / Q000235:genetics / Q000302:isolation & purification*; D040901:Proteomics / Q000379:methods*; D012825:Silicon / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation* / Q000379:methods; D015040:Zirconium / Q000737:chemistry
chemical_list: D063065:Organophosphonates; D010748:Phosphopeptides; D015040:Zirconium; D012825:Silicon