title: Hydrophilic Carboxyl Cotton Chelator for Titanium(IV) Immobilization and Its Application as Novel Fibrous Sorbent for Rapid Enrichment of Phosphopeptides.
abstract: Sample preparation methods with high selectivity, efficiency, and matrix resistance are essential for phosphoproteomic analysis. In this study, carboxyl cotton chelator-titanium(IV) (CCC-Ti4+) fibers, a novel CCC-based fibrous sorbent with excellent biocompatibility, were successfully synthesized on the basis of the coordination effect between double carboxyl groups on CCC and Ti4+. The synthesis of CCC-Ti4+ fibers was easy, and the incorporated titanium content was high. On the basis of immobilized metal ion affinity chromatography (IMAC), CCC-Ti4+ fibers were used for specific capture of phosphopeptides using a lab-in-syringe solid-phase extraction (SPE) from multiple biological samples, including standard protein digests, nonfat milk digests, human serum, and animal tissue. The proposed sorbent exhibited high selectivity (β-casein/BSA=1:1000) and good sensitivity (10 fmol) in phosphopeptides analysis. Meanwhile, the lab-in-syringe SPE greatly simplified the entire process of enrichment. Thanks to the good biocompatibility of CCC-based material, CCC-Ti4+ fibers showed excellent performance in phosphopeptide enrichment from protein-rich human serum. Finally, CCC-Ti4+ fibers were applied for selective capture of phosphopeptides from tryptic digests of rat brain lysate followed by LC-MS/MS analysis. Using the proposed method, we identified 3950 unique phosphosites from 1 mg of rat brain in a single experiment, which is much better than previously reported IMAC-based strategies. Taken together, this efficient method will find broad application in large-scale phosphoproteomics analysis because of the rapid (3 min) convenient procedure and excellent performance.
authors.affiliation: †Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Xiao-Mei
authors.initials: XM
authors.lastname: He
authors.affiliation: ‡Wuhan Institute of Biotechnology, Wuhan 430072, P.R. China.
authors.forename: Xi
authors.initials: X
authors.lastname: Chen
authors.affiliation: †Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Gang-Tian
authors.initials: GT
authors.lastname: Zhu
authors.affiliation: †Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.affiliation: †Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Bi-Feng
authors.initials: BF
authors.lastname: Yuan
authors.affiliation: †Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, P.R. China.
authors.forename: Yu-Qi
authors.initials: YQ
authors.lastname: Feng
mesh_terms: D000327:Adsorption; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry; D001921:Brain / Q000378:metabolism; D002614:Chelating Agents / Q000737:chemistry*; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D032561:Cotton Fiber; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008670:Metals / Q000737:chemistry; D008892:Milk / Q000737:chemistry; D010748:Phosphopeptides / Q000032:analysis / Q000097:blood / Q000302:isolation & purification*; D040901:Proteomics; D051381:Rats; D052616:Solid Phase Extraction; D053719:Tandem Mass Spectrometry; D014025:Titanium / Q000737:chemistry*
chemical_list: D001798:Blood Proteins; D002614:Chelating Agents; D008670:Metals; D010748:Phosphopeptides; D014025:Titanium
keywords: carboxyl cotton chelator-Ti4+; human serum; immobilized metal ion affinity chromatography; phosphopeptide enrichment; rat brain tissue