title: Selective on-line serum peptide extraction and multidimensional separation by coupling a restricted-access material-based capillary trap column with nanoliquid chromatography-tandem mass spectrometry.
abstract: As the serum peptidome gets increasing attention for biomarker discovery, one of the important issues is how to efficiently extract the peptides from highly complex human serum for peptidome analysis. Here we developed a fully automated platform for direct injection, on-line extraction, multidimensional separation and MS detection of peptides present in human serum. A capillary SPE column packed with a novel mix mode restricted access material (RAM) exhibiting strong cation exchange and size exclusion chromatography (SCX/SEC) properties were coupled with a nanoliquid chromatography-mass spectrometry (nanoLC-MS) system. The capillary SPE column excludes the high abundant serum proteins such as HSA by size exclusion chromatography and simultaneously extracts the low molecular weight peptides by binding to sulfonic acid residues. Subsequently, the trapped peptides are eluted to a capillary LC column packed with a RP-C18 stationary phase. After injection of only 2 microL human serum to the one-dimensional nanoLC-MS system around 400 peptides could be identified. When conducting a multidimensional separation, the described SCX/SEC/RP-MS platform allows the separation and identification of 1286 peptides present in human serum by the injection and on-line processing of 20 microL human serum sample.
authors.affiliation: CAS Key Laboratory of Separation Science for Analytical Chemistry, National Chromatographic R&A Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
authors.forename: Lianghai
authors.initials: L
authors.lastname: Hu
authors.forename: Karl-Siegfried
authors.initials: KS
authors.lastname: Boos
authors.forename: Mingliang
authors.initials: M
authors.lastname: Ye
authors.forename: Ren'an
authors.initials: R
authors.lastname: Wu
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D008970:Molecular Weight; D010455:Peptides / Q000097:blood* / Q000302:isolation & purification*; D040901:Proteomics / Q000379:methods*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010455:Peptides