title: Facile synthesis of guanidyl-functionalized magnetic polymer microspheres for tunable and specific capture of global phosphopeptides or only multiphosphopeptides.
abstract: The highly selective and efficient capture of heterogeneous types of phosphopeptides is critical for comprehensive and in-depth phosphoproteome analysis, but it still remains a challenge since the lack of affinity material with large binding capacity and controllable specificity. Here, a new affinity material was prepared to improve the enrichment capacity and endue the tunable specificity by introducing guanidyl onto poly(glycidyl methacrylate) (PGMA) modified Fe3O4 microsphere (denoted as Fe3O4@PGMA-Guanidyl). The thick polymer shell endows the composite microsphere with large amount of guanidyl and is beneficial to enhancing the affinity interaction between phosphopeptides and the material. Interestingly, the Fe3O4@PGMA-Guanidyl possesses tunable enriching ability for global phosphopeptides or only multiphosphopeptides through simple regulation of buffer composition. The composite has large enrichment capacity (200 mg g(-1)), extremely high detection sensitivity (0.5 fmol), high enrichment recovery (91.30%), great specificity, and rapid magnetic separation. Moreover, the result of the application to capture of phosphopeptides from tryptic digest of nonfat milk has demonstrated the great potential of Fe3O4@PGMA-Guanidyl in detection and identification of low-abundance phosphopeptides of interest in biological sample.
authors.affiliation: Shanghai Key Laboratory of Functional Materials Chemistry, Department of Chemistry and Molecular Engineering, East China University of Science and Technology , Shanghai 200237, China.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Xiong
authors.forename: Yajing
authors.initials: Y
authors.lastname: Chen
authors.forename: Lingyi
authors.initials: L
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Ren
authors.forename: Quanqing
authors.initials: Q
authors.lastname: Zhang
authors.forename: Mingliang
authors.initials: M
authors.lastname: Ye
authors.forename: Weibing
authors.initials: W
authors.lastname: Zhang
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D003460:Crystallization / Q000379:methods; D019791:Guanidine; D060526:Magnetic Fields; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008422:Materials Testing; D008863:Microspheres; D010316:Particle Size; D010748:Phosphopeptides / Q000737:chemistry* / Q000302:isolation & purification*; D011108:Polymers / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry*
chemical_list: D058185:Magnetite Nanoparticles; D010748:Phosphopeptides; D011108:Polymers; D011109:Polymethacrylic Acids; C042535:polyglycidyl methacrylate; D019791:Guanidine
keywords: guanidyl; magnetic microspheres; mass spectrum; phosphorylated peptides; tunable enrichment ability