New hydrophilic material based on hydrogel polymer for the selective enrichment of intact glycopeptides from serum protein digests

Facial on-line enrichment of glycoproteins by capillary electrophoresis with boronate-functionalized poly(glycidyl methacrylate) microparticles coated column

A facial and rapid method for glycoproteins enrichment by capillary electrophoresis was developed. The 3-aminophenylboronic acid-functionalized poly(glycidyl methacrylate) microparticles (PGMA@APBA) were attached to the capillary inlet (length of ∼1.5 cm) by electrostatic self-assemble action to prepare a partially coated capillary column. The process is simple and reversible, allowing for easy renewal of the PGMA@APBA coating when its enrichment efficiency decreases. By utilizing the coated column, glycoproteins can be enriched within 2 min. The column exhibits a specific enrichment for glycoproteins and can be consecutively used for approximately 60 runs. The relative standard deviations (RSDs) of peak area of run-to-run (n = 5) and batch-to-batch (n = 3) were 1.5 % and 1.0%, respectively. The method was successfully applied to enrich glycoproteins from 1 × 1012-fold diluted real egg white sample, indicating its practical applicability.

Dual-functionalized two-dimensional metal-organic framework composite with highly hydrophilicity for effective enrichment of glycopeptides

Protein glycosylation research is currently focused on the development of various functionalized materials that can effectively enrich the levels of glycopeptides in samples. However, most of these materials possess limited glycopeptide-specific recognition sites because of large steric hindrance, unsuitable mass transfer kinetics, and relatively low surface areas. Herein, a highly hydrophilic two-dimensional (2-D) metal-organic framework (MOF) nanosheet modified with glutathione (GSH) and l-cysteine (l-Cys) (denoted as Zr-Fc MOF@Au@GC) has been synthesized for efficient glycopeptide enrichment. Using this composite material, 39 and 44 glycopeptides from horseradish peroxidase (HRP) and human serum immunoglobulin G (IgG) digests were detected, respectively, which represents a higher efficiency for glycopeptide enrichment from model glycoprotein digests than has been previously reported. The material Zr-Fc MOF@Au@GC exhibited ultra-high sensitivity (0.1 fmol/µL), excellent selectivity (weight ratio of HRP tryptic digest to bovine serum albumin (BSA) tryptic digest = 1:2000), good binding capacity (200 mg/g), satisfactory reusability, and long-term storage capacity. In addition, 655 glycopeptides corresponding to 366 glycoproteins were identified from human serum samples. To the best of our knowledge, this is the largest number of glycoproteins detected in human serum samples to date. These results indicated that Zr-Fc MOF@Au@GC has the potential to be used for the enrichment of glycopeptides in biological samples and the analysis of protein glycosylation.

Identification of Core-Fucosylated Glycoproteins by Single-Step Truncation of N-Glycans

Alpha-1,6 core fucosylation (CF) is a unique glycoform of N-glycans, and studies showed that CF modifications are involved in the occurrence and progression of various diseases and may provide potential disease biomarkers. Current strategies for the CF glycoproteome are often based on multistep enrichment of glycoproteins or glycopeptides and sequential cleavage with different glycosidases to truncate the N-glycans. Although the detection ability of low-abundance glycoproteins is improved, sample loss, high cost, and the time-consuming multistep operation also affect the reproducibility of results and the practicality of the method. Here we developed a single-step truncation (SST) strategy and evaluated its potential for the CF glycoproteome of human serum. The SST strategy has the advantages of fewer operational steps, lower cost, higher number of identifications, and better quantitative stability compared with previous approaches and provides an efficient solution for large-scale quantitative analysis of the CF glycoproteome. © 2024 Wiley Periodicals LLC. Basic Protocol 1: Single-step truncation strategy for core fucosylation glycoproteome analysis in human serum Basic Protocol 2: Liquid chromatography-tandem mass spectrometry quantification of site-specific core fucosylation glycopeptides Alternate Protocol: Pretreatment of cellular samples of core fucosylation glycoproteome with single-step truncation strategy.

Hydroxyethyl Cellulose-Based Hydrogels as Controlled Release Carriers for Amorphous Solid Dispersion of Bioactive Components of Radix Paeonia Alba

Radix Paeoniae Alba (RPA) has been used extensively in Chinese traditional medicine to treat gastrointestinal disorders, immune-modulating diseases, cancers, and numerous other conditions. A few of its active components include paeoniflorin, albiflorin, lactiflorin, and catechin. However, their therapeutic effectiveness is compromised by poor pharmacokinetic profiles, low oral bioavailability, short half-lives, and poor aqueous solubility. In this study, hydroxyethyl cellulose-grafted-2-acrylamido-2-methylpropane sulfonic acid (HEC-g-AMPS) hydrogels were successfully prepared for the controlled release of Radix Paeonia Alba-solid dispersion (RPA-SD). A total of 43 compounds were identified in RPA-SD using UHPLC-Q-TOF-MS analysis. The hydrogel network formation was confirmed by FTIR, TGA, DSC, XRD, and SEM. Hydrogels' swelling and drug release were slightly higher at pH 1.2 (43.31% swelling, 81.70% drug release) than at pH 7.4 (27.73% swelling, 72.46% drug release) after 48 h. The gel fraction, drug release time and mechanical strength of the hydrogels increased with increased polymer and monomer concentration. Furthermore, the hydrogels were porous (84.15% porosity) and biodegradable (8.9% weight loss per week). Moreover, the synthesized hydrogels exhibited excellent antimicrobial and antioxidative properties.

Differential analysis of core-fucosylated glycoproteomics enabled by single-step truncation of N-glycans

Alpha-1,6 fucosylation of N-glycans (core fucosylation, CF) represents a unique form of N-glycans and is widely involved in disease progression. In order to accurately identify CF glycoproteins, several approaches have been developed based on sequential cleavage with different glycosidases to truncate the N-glycans. Since multi-step sample treatments may introduce quantitation bias and affect the practicality of these approaches in large-scale applications. Here, we systematically evaluated the performance of the single-step treatment of intact glycopeptides by endoglycosidase F3 for CF glycoproteome. The single-step truncation (SST) strategy demonstrated higher quantitative stability and higher efficiency compared with previous approaches. The strategy was further practiced on both cell lines and serum samples. The dysregulation of CF glycopeptides between preoperative and postoperative serum from patients with pancreatic ductal adenocarcinoma was revealed, and the CF modifications of BCHE_N369, CDH5_N112 and SERPIND1_N49 were found to be potential prognostic markers. This study thus provides an efficient solution for large-scale quantitative analysis of the CF glycoproteome.

A novel hydrophilic polymer-coated magnetic nanomaterial based on the HILIC strategy for fast separation of glycopeptides and glycosylated exosomes

Novel hydrophilic poly(N, N-methylenebisacrylamide/1,2-epoxy-5-hexene) coated magnetic nanospheres functionalized with 2-aminopurine (denoted as Fe3O4@poly(MBA/EH)@2AP) for enriching glycopeptides and glycosylated exosomes were successfully obtained using a simple and green method on the basis of the HILIC (hydrophilic interaction liquid chromatography) enrichment strategy. The high density of polar groups endows the material with amazing hydrophilicity, enabling the nanomaterial to successfully capture glycopeptides and glycosylated exosomes within 1 min. Meanwhile, the materials demonstrated great sensitivity (0.01 fmol/μL), good loading capability (125 μg/mg), high selectivity (BSA:HRP = 1000:1), and repeatability (more than 10 times). Besides, the material was applied in the analysis of bio-samples, a total of 290 glycosylated peptides and 184 glycosylation sites mapping to 185 glycoproteins were identified in the serum of uremic patients. Besides, 42 glycopeptides were enriched from the saliva of healthy people. At the same time, it was verified by TEM and western blot that the complete glycosylated exosomes were successfully captured from the serum of the uremic patients. All experiments have demonstrated that Fe3O4@poly(MBA/EH)@2AP has a promising future in practical applications.