Glycosylation is one of the most important post-translational modifications of proteins, which plays an important role in the structure and function of proteins. However, due to the diversity of glycopeptide forms and low abundance, it is extraordinarily challenging to capture and separate glycopeptides with highly selectively from complex biological samples with mass spectrometric analysis. Here, we synthesized a new type of hydrophilic composite based on electrostatic interaction, which has been proved to be effective in immobilizing cationic cellulose on graphene oxide-dopamine carrier (expressed as GO-DA-JR), for highly specific enrichment of N-glycopeptide. The introduction of cationic cellulose not only provides a perfect surface charge for the composite, but also provides a greater ability to enrich glycosylated peptides. 32 glycopeptides from human serum immunoglobulin G tryptic digests were observed with greatly improved signal-to-noise ratio (S/N), while it also presents a high performance in anti-interfering enrichment of glycopeptides from complex samples containing 100-fold bovine serum albumin tryptic digests. In addition, GO–DA-JR has higher sensitivity (1 fmol/μL IgG) and better enrichment capacity ability (up to 150 mg/g). Meanwhile, the results of glycopeptides enrichment and glycosylation analysis from human serum also show the good enrichment selectivity from real biological samples. This work exhibits high selectivity, high sensitivity, good stability and operability, indicating its potential for applications of glycopeptides enrichment in post-translational modification proteomics.

糖基化是蛋白质最重要的翻译后修饰之一，其在蛋白质的结构和功能中起重要作用。然而，由于糖肽形式的多样性和低丰度，通过质谱分析从复杂的生物样品中高度选择性地捕获和分离糖肽异常困难。在这里，我们基于静电相互作用合成了一种新型的亲水复合材料，已被证明可有效地将阳离子纤维素固定在氧化石墨烯-多巴胺载体（表示为GO-DA-JR）上，以高度特异性地富集N-糖肽。阳离子纤维素的引入不仅为复合材料提供了理想的表面电荷，而且还提供了更大的富集糖基化肽的能力。观察到来自人血清免疫球蛋白G胰蛋白酶消化物中的32种糖肽具有显着改善的信噪比（S / N），同时它还具有抗干扰富集包含100倍牛血清白蛋白的复杂样品中糖肽的高效能胰蛋白酶消化物。此外，GO–DA-JR具有更高的灵敏度（1 fmol /μLIgG）和更好的富集能力（高达150 mg / g）。同时，人血清中糖肽富集和糖基化分析的结果也显示出对真实生物样品的良好富集选择性。这项工作表现出高选择性，高灵敏度，良好的稳定性和可操作性，表明其潜力的糖肽富集在翻译后修饰蛋白质组学中的应用。