A capillary column packed with a zirconium(IV)-based organic framework for enrichment of endogenous phosphopeptides

• Published in: Mikrochimica acta (1966) Vol. 185; no. 12; pp. 562 - 8
• Main Authors: Lin, Haizhu, Chen, Hemei, Shao, Xi, Deng, Chunhui
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.12.2018; Springer; Springer Nature B.V
• Subjects: Analysis; Analytical Chemistry; Casein; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Ionization; Ions; Mass spectrometry; Metal-organic frameworks; Microengineering; Microspheres; Nanochemistry; Nanotechnology; Original Paper; Phosphates; Post-translational modification; Saliva; Selectivity; Silicon dioxide; Zirconium; MALDI-TOF MS; MOF; Human saliva; Phosphopeptide; Polydopamine; Metal oxide affinity chromatography; Phosphoproteome; Size exclusion effect; Mass spectrometry; On-column enrichment
• ISSN: 0026-3672; 1436-5073; 1436-5073
• DOI: 10.1007/s00604-018-3109-7

A zirconium(IV)-based metal organic framework (Zr-MOF) was deposited on polydopamine-coated silica microspheres to form microspheres of type SiO 2 @PDA@Zr-MOF. These were packed into capillary columns for enrichment of phosphopeptides. The column was off-line coupled to both matrix-assisted laser desorption/ionization time of flight mass spectrometry and LC-ESI-MS/MS. The method has a detection limit as low as 4 fmol of β-casein digest and a selectivity as high as 1:1000 (molar ratio of β-casein and BSA digest). It was applied to the analysis of human saliva. In total, 240 endogenous phosphopeptides were identified in only 25 μL human saliva. Graphical abstract A zirconium-based metal organic framework (Zr-MOF) was modified outside of polydopamine-coated silica microspheres to form microspheres named SiO 2 @PDA@Zr-MOF. Then they were packed in capillary columns for selective enrichment of phosphopeptides via interaction between Zr-O clusters and phosphate groups. The pre-concentration resulted in a better detection of phosphopeptides by mass spectrometry. Tris: Tris(hydroxymethyl)aminomethane; DMF: Dimethyl Formamide; Zr-MOF: Zirconium(IV)-organic framework; MOAC: Metal oxide affinity chromatography.