title: Highly specific phosphopeptide enrichment by titanium(IV) cross-linked chitosan composite.
abstract: Natural chitosan was applied as supporting material for Ti(IV) based immobilized metal ion affinity chromatographic (IMAC) material (Ti-CTS). Compared with other polymer based IMAC, Ti-CTS can save the cockamamie synthesis procedures and be easy to obtain. The morphology, surface area, pore volume and elemental composition of Ti-CTS were revealed by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) method and X-ray photoelectron spectroscopy (XPS). Tryptic digest products from several standard proteins and two real samples (non-fat milk and serum) were enriched using Ti-CTS to demonstrate the efficiency of this method. The results showed that this composite enables high sensitive and selective phosphopeptide enrichment from casein variants, non-fat milk and human serum. Furthermore, multi-phosphorylated peptides with three serine phospholated sites (S*S*S*) demonstrated high affinity to Ti-CTS. Hence, this method had great potential for future studies of complex phosphoproteomes and especially multi-phosphorylated peptides.
authors.affiliation: Research Centre of Analysis and Test, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wu
authors.affiliation: Research Centre of Analysis and Test, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Jiani
authors.initials: J
authors.lastname: Shi
authors.affiliation: Research Centre of Analysis and Test, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Chuanjing
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Research Centre of Analysis and Test, East China University of Science and Technology, Shanghai 200237, China. Electronic address: zlf@ecust.edu.cn.
authors.forename: Lingfan
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Research Centre of Analysis and Test, East China University of Science and Technology, Shanghai 200237, China.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Du
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010748:Phosphopeptides / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014025:Titanium / Q000737:chemistry*
chemical_list: D010748:Phosphopeptides; D048271:Chitosan; D014025:Titanium
keywords: Chitosan; IMAC; MALDI TOF MS; Phosphopeptide enrichment