An amino-rich polymer-coated magnetic nanomaterial for ultra-rapid separation of phosphorylated peptides in the serum of Parkinson’s disease patients

The elucidation of disease pathogenesis can be achieved by analyzing the low-abundance phosphopeptides in organisms. Herein, we developed a novel and easy-to-prepare polymer-coated nanomaterial. By improving the hydrophilicity and spatial conformation of the material, we effectively enhanced the adsorption of phosphopeptides and demonstrated excellent enrichment properties. The material was able to successfully enrich the phosphopeptides in only 1 min. Meanwhile, the material has high selectivity (1:2000), good loading capacity (100 μg/mg), excellent sensitivity (0.5 fmol), and great acid and alkali resistance. In addition, the material was applied to real samples, and 70 phosphopeptides were enriched from the serum of Parkinson’s disease (PD) patients and 67 phosphopeptides were enriched from the serum of normal controls. Sequences Logo showed that PD is probably associated with threonine, glutamate, serine, and glutamine. Finally, gene ontology (GO) analysis was performed on phosphopeptides enriched in PD patients’ serum. The results showed that PD patients expressed abnormal expression of the cholesterol metabolic process and cell–matrix adhesion in the biological process (BP), endoplasmic reticulum and lipoprotein in the cellular component (CC), and heparin-binding, lipid-binding, and receptor-binding in the molecular function (MF) as compared with normal individuals. All the experiments indicate that the nanomaterials have great potential in proteomics studies.