Postsynthesis of zwitterionic hydrophilic composites for enhanced enrichment of N‐linked glycopeptides from human serum

Abstract

Rationale Glycosylation of proteins plays an important role in life activities, but the concentration of naturally occurring glycopeptides is usually relatively low, and glycosylation has microfacies heterogeneity, so direct mass spectrometry is not feasible. Therefore, selective enrichment of glycopeptides before mass spectrometry has turned into an urgent problem to be resolved. Methods Herein, the zwitterionic L‐cysteine functionalized hydrophilic graphene oxide composite (GO@PDA@MIL‐125‐NH2@Au@L‐Cys) was prepared via a postsynthetic method. The obtained material was used for glycopeptide enrichment. The enriched peptides were then detected using matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) to demonstrate the enrichment performance of the material. Results In the actual enrichment process, GO@PDA@MIL‐125‐NH2@Au@L‐Cys nanomaterials exhibited high selectivity (1:1000), outstanding sensitivity (0.5 fmol), and excellent repeatability for the enrichment of glycopeptides. In addition, the proposed material showed good performance in the enrichment of glycopeptides from complex biosamples; 56 glycopeptides were detected from 2 μL of human serum using MALDI‐TOFMS. Conclusions The experimental results showed that GO@PDA@MIL‐125‐NH2@Au@L‐Cys exhibited excellent performance on glycopeptide analysis. It has great potential in the enrichment of glycopeptides and provides new ideas for synthetic materials with better enrichment properties in the future.

Enrichment of glycopeptides using environmentally friendly wood materials

“…In order to further investigate the selectivity of glycopeptide enrichment using different tips, sample mixtures of IgG digest and bovine serum albumin (BSA) digest with different weight mixing ratios were loaded onto the three kinds of tips for comparison. 18,37 Sample mixtures with the following IgG digest/BSA digest (IgG/BSA) weight mixing ratios were enriched: 1/10, 1/50, 1/100 and 1/150, corresponding to molar ratios of 1/23, 1/115, 1/230 and 1/345. After mixing the IgG digest with the BSA digest, a lot of non-glycopeptides could be detected in the elution fractions together with glycopeptides, no matter what kind of tip was used for enrichment ( Fig.…”

Modified Carbon Nanotubes Decorated with ZIFs as New Immobilized Metal Ion Affinity Chromatography Platform for Enrichment of Phosphopeptides

“…A larger specific surface area means more anchor sites for subsequent materials, which can also be seen from the determination of the Zn element content of EDX. Similarly, Liu et al [36] . constructed GO@PDA@MIL‐125@Au@L−Cys using graphene as the base material showed a more outstanding performance than general magnetic microspheres during glycopeptide enrichment experiments, and both the limit of detection and selectivity were superior to an order of magnitude.…”

“…A larger specific surface area means more anchor sites for subsequent materials, which can also be seen from the determination of the Zn element content of EDX. Similarly, Liu et al [36] constructed GO@PDA@MIL-125@Au@LÀ Cys using graphene as the base material showed a more outstanding performance than general magnetic microspheres during glycopeptide enrichment experiments, and both the limit of detection and selectivity were superior to an order of magnitude. Through these comparisons, we can clearly see that the materials with a larger specific surface area as the substrate have preferable enrichment performance, which provides a clearer choice for us to pursue more extreme and superior phosphopeptides enrichment performance.…”

“…[31] Encouraging in our previous research, [32] branched-chain PEI was used to stabilize ZIF-8 on the surface of the PDA-modified magnetic microspheres, which showed good performance in the phosphopeptides enrichment. Furthermore, we have compared in a series of studies [33][34][35][36] and found that among the materials that use the same core enrichment function group, the materials that use a larger specific surface area as the substrate showing better performance on enrichment of phosphopeptide: the lower limit of detection and the higher selectivity. As we all know, since the discovery of the electron microscope expert Iijima of EC company in 1991, [37] carbon nanotube, a allotropes of carbon nanostructure, the ratio of length to diameter was greater than 1,000,000 or even more.…”

Hydrophilic carrageenan functionalized magnetic carbon‐based framework linked by silane coupling agent for the enrichment of N‐glycopeptides from human saliva

“…Glycoprotein is composed of protein and sugar chains connected by covalent bonds and has high hydrophilicity, while nonglycosylated proteins are more hydrophobic, so the difference in hydrophilicity can be used to achieve glycoprotein enrichment. As a result, hydrophilic nanomaterials with a large number of hydrophilic groups have been explored and achieved good results in glycopeptides enrichment [25][26][27][28]. Recently, carbon-based materials are considered as convenient scaffolds for obtaining hybrid materials, not only because of their large specific surface area but also because they can be postmodified to have properties of magnetism, hydrophilicity, biocompatibility, and so on [29].…”