Related Experiment Video
Updated: Feb 10, 2026

Phosphopeptide Enrichment Coupled with Label-free Quantitative Mass Spectrometry to Investigate the Phosphoproteome in Prostate Cancer
Published on: August 2, 2018
Magnetic microspheres modified with Ti(IV) and Nb(V) for enrichment of phosphopeptides
Jiebing Jiang1, Xueni Sun2, Xiaojian She1
1Fudan University Affiliated Pudong Medical Center & Pharmaceutical Analysis Department, School of Pharmacy, Fudan University, Shanghai, 201203, China.
Abstract:
Magnetic microspheres (Fe3O4) were coated with polydopamine (PDA) and loaded with the metal ions Ti(IV) and Nb(V) to give a material of type Fe3O4@PDA-Ti/Nb. It is shown to be useful for affinity chromatography and for enrichment of phosphopeptides from both standard protein solutions and real samples. For comparison, such microspheres loaded with single metal ions only (Fe3O4@PDA-Ti and Fe3O4@PDA-Nb) and their physical mixtures were also investigated under identical conditions. The binary metal ion-loaded magnetic microspheres display better enrichment efficiency than the single metal ion-loaded microspheres and their physical mixture. Both multiphosphopeptides and monophosphopeptides can be extracted. The Fe3O4@PDA-Ti/Nb microspheres exhibit ultra-high sensitivity (the lowest detection amount being 2 fmol) and selectivity at a low mass ratio such as in case of β-casein/BSA (1:1000). Graphical abstract Magnetic microspheres (Fe3O4) were coated with polydopamine (PDA) and loaded with the metal ions Ti(IV) and Nb(V) to give a material of type Fe3O4@PDA-Ti/Nb. Results showed its great potential as an affinity probe in phosphoproteome research due to rapid magnetic separation of phosphopeptides, ultrahigh sensitivity and selectivity, and remarkable reusability.
Related Concept Videos
Imaging Studies IV: Magnetic Resonance Imaging
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
Pneumonia IV: Management
Bacterial Pneumonia Treatment
For bacterial pneumonia, antibiotics serve as the cornerstone of therapy. Initial treatment often begins with empirical antibiotics, tailored to the anticipated causative organism and adjusted based on culture results. Key antibiotic choices include:
Pulmonary Tuberculosis IV
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
Diversity of Archaea IV
Modified Boxplots
However, the box plot does not tell the reader about outliers - values that lie far from the center of the data. We can modify the standard box and whisker plot to identify the outliers and visualize the actual spread of the data in a sample.
Initially, we calculate the adjusted...

