title: Highly specific enrichment of phosphopeptides by zirconium dioxide nanoparticles for phosphoproteome analysis.
abstract: Large-scale characterization of phosphoproteins requires highly specific methods for the purification of phosphopeptides because of the low abundance of phosphoproteins and substoichiometry of phosphorylation. A phosphopeptide enrichment method using ZrO2 nanoparticles is presented. The high specificity of this approach was demonstrated by the isolation of phosphopeptides from the digests of model phosphoproteins. The strong affinity of ZrO2 nanoparticles to phosphopeptides enables the specific enrichment of phosphopeptides from a complex peptide mixture in which the abundance of phosphopeptides is two orders of magnitude lower than that of nonphosphopeptides. Superior selectivity of ZrO2 nanoparticles for the enrichment of phosphorylated peptides than that of conventional immobilized metal affinity chromatography was observed. Femtomole phosphopeptides from digestion products could be enriched by ZrO2 nanoparticles and can be well detected by MALDI mass spectrometric analysis. ZrO2 nanoparticles were further applied to selectively isolate phosphopeptides from the tryptic digestion of mouse liver lysate for phosphoproteome analysis by nanoliter LC MS/MS (nano-LC-MS/MS) and MS/MS/MS. A total of 248 defining phosphorylation sites and 140 phosphorylated peptides were identified by manual validation using a series of rigid criteria.
authors.affiliation: National Chromatographic R & A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, PR China.
authors.forename: Houjiang
authors.initials: H
authors.lastname: Zhou
authors.forename: Ruijun
authors.initials: R
authors.lastname: Tian
authors.forename: Mingliang
authors.initials: M
authors.lastname: Ye
authors.forename: Songyun
authors.initials: S
authors.lastname: Xu
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: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002364:Caseins / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D051379:Mice; D010047:Ovalbumin / Q000737:chemistry; D010748:Phosphopeptides / Q000302:isolation & purification*; D020543:Proteome / Q000032:analysis*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053719:Tandem Mass Spectrometry; D014357:Trypsin / Q000378:metabolism; D015040:Zirconium / Q000737:chemistry*
chemical_list: D002364:Caseins; D010748:Phosphopeptides; D020543:Proteome; D012710:Serum Albumin, Bovine; D010047:Ovalbumin; D015040:Zirconium; D014357:Trypsin; C028541:zirconium oxide