title: Size-exclusive magnetic graphene/mesoporous silica composites with titanium(IV)-immobilized pore walls for selective enrichment of endogenous phosphorylated peptides.
abstract: Developing an effective separation method is necessary for identifying low-abundant endogenous phosphorylated peptides with the removal of proteins. In this work, we prepared size-exclusive magnetic graphene/mesoporous silica composites with titanium(IV)-immobilized pore walls (denoted as Ti(4+)-MGMSs) for capturing endogenous phosphorylated peptides for mass spectrometry analysis. The introduction of hydrophilic polydopamine simplified the synthetic process of Ti(4+)-MGMSs, and the ordered mesoporous channels are beneficial to the trapping of endogenous phosphopeptides while large-size proteins are excluded. Furthermore, the magnetic performance greatly simplifies the entire process of enrichment. With all of the advances, the novel Ti(4+)-MGMSs present high enrichment efficiency either from the low concentration of β-casein tryptic digest (0.5 fmol/μL) or the mixture of β-casein tryptic digest and α-casein (or plus bovine serum albumin, with a mass ratio up to 1:500). Besides, Ti(4+)-MGMSs have also been successfully applied to enrich endogenous phosphorylated peptides from human serum and human saliva.
authors.affiliation: Department of Chemistry and Institutes of Biomedical Sciences, Fudan University , Shanghai 200433, China.
authors.forename: Nianrong
authors.initials: N
authors.lastname: Sun
authors.forename: Chunhui
authors.initials: C
authors.lastname: Deng
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002364:Caseins / Q000737:chemistry; D002417:Cattle; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D060526:Magnetic Fields; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification*; D010750:Phosphoproteins / Q000737:chemistry / Q000302:isolation & purification*; D016062:Porosity; D012463:Saliva / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D002364:Caseins; D010455:Peptides; D010750:Phosphoproteins; D012710:Serum Albumin, Bovine; D012822:Silicon Dioxide; D006108:Graphite; D014025:Titanium