Titanium‐containing magnetic mesoporous silica spheres: Effective enrichment of peptides and simultaneous separation of nonphosphopeptides and phosphopeptides

Abstract

Protein phosphorylation is a common posttranslational modification, and involved in many cellular processes. Like endogenous peptides, endogenous phosphopeptides contain many biomarkers of preclinical screening and disease diagnosis. In this work, titanium-containing magnetic mesoporous silica spheres were synthesized and applied for effective enrichment of peptides from both tryptic digests of standard proteins and human serum. Besides, the enriched peptides can be further separated into nonphosphopeptides and phosphopeptides by a simple elution. First, titanium-containing magnetic mesoporous silica spheres were synthesized by a sol-gel method and found to have high surface area, narrow pore size distribution, and useful magnetic responsivity. Then, as the prepared material was used for selective capturing of phosphopeptides, it demonstrated to have higher selectivity than commercial titanium dioxide. Moreover, via combination of size-exclusion mechanism, hydrophobic interaction, and affinity chromatography, titanium-containing magnetic mesoporous silica spheres were successfully applied to simultaneously extract and separate nonphosphopeptides and phosphopeptides from standard protein digestion and human serum.

Modification of Luffa Sponge for Enrichment of Phosphopeptides

“…Eighteen phosphopeptides from α-casein digest (Figure 5b) and nine from β-casein digest (Figure 5d) were detected. The number of phosphopeptides enriched from α-casein was improved in comparison with the previously reported results enriched by commercial TiO 2 [38,39], in which thirteen phosphopeptides were identified. The information about the phosphopeptides involved in this paper is displayed in Supplementary Table S2.…”

Recent advances in enrichment and separation strategies for mass spectrometry‐based phosphoproteomics

“…Magnetic beads have attracted a great deal of interest due to the simplicity for isolating phosphopeptides from a sample solution by an external magnetic field and provide a high‐throughput platform for automated enrichment processes . Although magnetic nonporous beads with different metal ions immobilized have been successfully used for various biological samples and are commercially available , magnetic mesoporous beads with high‐density pores and large surface areas have gained increasing attention in the past five years . Zirconium‐containing magnetic mesoporous beads have been synthesized and applied for enriching phosphopeptides by directly coating mesoporous silica on to Fe 3 O 4 magnetic microspheres following addition of phosphate to chelate with Zr 4+ ions .…”

Quinine Derivative Bonded the Hybrid Mesoporous Silicas Chiral Stationary Phase: Preparation and Application in Liquid Chromatography

“…4 APEPMOs have the advantages of mesoporous silicas such as high surface area, high loading capacity, narrow pore size distribution. However, they had better permeability and certain advantages in fast analysis.…”