title: Hydrazide functionalized core-shell magnetic nanocomposites for highly specific enrichment of N-glycopeptides.
abstract: In view of the biological significance of glycosylation for human health, profiling of glycoproteome from complex biological samples is highly inclined toward the discovery of disease biomarkers and clinical diagnosis. Nevertheless, because of the existence of glycopeptides at relatively low abundances compared with nonglycosylated peptides and glycan microheterogeneity, glycopeptides need to be highly selectively enriched from complex biological samples for mass spectrometry analysis. Herein, a new type of hydrazide functionalized core-shell magnetic nanocomposite has been synthesized for highly specific enrichment of N-glycopeptides. The nanocomposites with both the magnetic core and the polymer shell hanging high density of hydrazide groups were prepared by first functionalization of the magnetic core with polymethacrylic acid by reflux precipitation polymerization to obtain the Fe3O4@poly(methacrylic acid) (Fe3O4@PMAA) and then modification of the surface of Fe3O4@PMAA with adipic acid dihydrazide (ADH) to obtain Fe3O4@poly(methacrylic hydrazide) (Fe3O4@PMAH). The abundant hydrazide groups toward highly specific enrichment of glycopeptides and the magnetic core make it suitable for large-scale, high-throughput, and automated sample processing. In addition, the hydrophilic polymer surface can provide low nonspecific adsorption of other peptides. Compared to commercially available hydrazide resin, Fe3O4@PMAH improved more than 5 times the signal-to-noise ratio of standard glycopeptides. Finally, this nanocomposite was applied in the profiling of N-glycoproteome from the colorectal cancer patient serum. In total, 175 unique glycopeptides and 181 glycosylation sites corresponding to 63 unique glycoproteins were identified in three repeated experiments, with the specificities of the enriched glycopeptides and corresponding glycoproteins of 69.6% and 80.9%, respectively. Because of all these attractive features, we believe that this novel hydrazide functionalized core-shell magnetic nanocomposite will shed new light on the profiling of N-glycoproteome from complex biological samples in high throughput.
authors.affiliation: Shanghai Cancer Center and Institutes of Biomedical Sciences, Fudan University , Shanghai 200032, P. R. China.
authors.forename: Liting
authors.initials: L
authors.lastname: Liu
authors.forename: Meng
authors.initials: M
authors.lastname: Yu
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Changchun
authors.initials: C
authors.lastname: Wang
authors.forename: Haojie
authors.initials: H
authors.lastname: Lu
mesh_terms: D002851:Chromatography, High Pressure Liquid; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology; D052203:Ferrosoferric Oxide / Q000737:chemistry; D006020:Glycopeptides / Q000032:analysis*; D006023:Glycoproteins / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D006834:Hydrazines / Q000737:chemistry*; D008280:Magnetics; D053761:Nanocomposites / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry; D040901:Proteomics; D059629:Signal-To-Noise Ratio; D053719:Tandem Mass Spectrometry
chemical_list: D006020:Glycopeptides; D006023:Glycoproteins; D006834:Hydrazines; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid; C029424:hydrazine; D052203:Ferrosoferric Oxide