title: Profiling of endogenous serum phosphorylated peptides by titanium (IV) immobilized mesoporous silica particles enrichment and MALDI-TOFMS detection.
abstract: Phosphorylation is one of the most important post-translational modifications of proteins, which modulates a wide range of biological functions and activities of proteins. The phosphorylation of proteins is also associated with the pathway of cancer cells. We have previously enriched the low molecular weight proteome from human plasma based on the combination of size exclusion and adsorption mechanism by using highly ordered mesoporous silica particles. Herein, highly ordered mesoporous silica particles were modified with titanium phosphonate to selectively capture the phosphopeptides from complex peptide and protein mixtures. The limit of detection for phosphopeptides from beta-casein and standard phosphopeptide spiked in human serum was as low as 1.25 fmol based on MALDI-TOFMS detection. The modified mesoporous silica particles were further used to enrich phosphopeptides from serum of hepatocellular carcinoma patients and healthy individuals and then analyzed with MALDI-TOFMS. The combination of isobaric tagging for relative and absolute quantitation labeling with MALDI-TOFMS/MS was further applied to validate the serum phosphopeptide profiling result of MALDI-TOFMS. The profiling of the serum phosphopeptides between the cancer patients and healthy persons was distinguishingly different, which indicated the potential ability of this technique for cancer diagnosis and biomarker discovery. The approach developed here would be applicable to other biological samples and a wide variety of diseases.
authors.affiliation: 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: Houjiang
authors.initials: H
authors.lastname: Zhou
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Li
authors.forename: Shutao
authors.initials: S
authors.lastname: Sun
authors.forename: Lihai
authors.initials: L
authors.lastname: Guo
authors.forename: Mingliang
authors.initials: M
authors.lastname: Ye
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Tian
authors.forename: Jianren
authors.initials: J
authors.lastname: Gu
authors.forename: Shengli
authors.initials: S
authors.lastname: Yang
authors.forename: Hanfa
authors.initials: H
authors.lastname: Zou
mesh_terms: D000328:Adult; D001798:Blood Proteins / Q000032:analysis* / Q000737:chemistry; D006528:Carcinoma, Hepatocellular / Q000097:blood; D002364:Caseins / Q000032:analysis / Q000737:chemistry; D005340:Fibrinogen / Q000032:analysis* / Q000737:chemistry; D006801:Humans; D008113:Liver Neoplasms / Q000097:blood; D063065:Organophosphonates / Q000737:chemistry; D010446:Peptide Fragments / Q000032:analysis / Q000737:chemistry; D010748:Phosphopeptides / Q000032:analysis* / Q000737:chemistry; D010766:Phosphorylation; D012822:Silicon Dioxide / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014025:Titanium / Q000737:chemistry*
chemical_list: D001798:Blood Proteins; D002364:Caseins; D063065:Organophosphonates; D010446:Peptide Fragments; D010748:Phosphopeptides; D012822:Silicon Dioxide; D005340:Fibrinogen; D014025:Titanium