Quantitative analysis of glycans is an emerging field in glycomic research. Herein we present a rapid and effective dual-labeling strategy, in the combination of isotopic derivatization of N-glycosylamine-based glycans by d0/d5-benzoyl chloride and methylamidation of sialic acids, to relatively quantify both neutral and sialylated N-glycans simultaneously by MALDI-MS. The derivatization efficiencies were increased by microwave-accelerated deglycosylation which not only largely reduce the time of glycoprotein deglycosylation but also inhibit the hydrolysis of intermediate glycosylamines produced by PNGase F digestion. Three model glycoproteins, including RNase B, bovine fetuin and IgG from human serum, were applied to validate this technique. Results showed that the glycans from microgram level of glycoprotein can be successfully quantified with high reproducibility and the whole time of analytical procedure was shortened to 4 h. Furthermore, this proposed method was applied for the comparative analysis of N-glycans from serum of healthy donors and multiple myeloma patients. It was found that five N-glycans may be as the potential biomarkers for rapid detection of early multiple myeloma, indicating the feasibility of this strategy in monitoring subtle quantitative differences of serum glycomics.

中文翻译：

---

通过 MALDI-MS 使用稳定同位素标记的 d0/d5-苯甲酰氯对中性和唾液酸化 N-聚糖进行相对定量

聚糖的定量分析是糖组学研究中的一个新兴领域。在此，我们提出了一种快速有效的双标记策略，结合 d0/d5-苯甲酰氯对基于 N-糖基胺的聚糖的同位素衍生化和唾液酸的甲基酰胺化，通过以下方式同时相对量化中性和唾液酸化的 N-聚糖MALDI-MS。微波加速去糖基化提高了衍生效率，这不仅大大减少了糖蛋白去糖基化的时间，而且抑制了 PNGase F 消化产生的中间体糖基胺的水解。三种模型糖蛋白，包括 RNase B、牛胎球蛋白和人血清中的 IgG，被用于验证该技术。结果表明，微克级糖蛋白聚糖可以成功定量，重现性高，整个分析过程时间缩短至 4 小时。此外，该方法还用于对健康供体和多发性骨髓瘤患者血清中的 N-聚糖进行比较分析。发现五种N-聚糖可能作为快速检测早期多发性骨髓瘤的潜在生物标志物，表明该策略在监测血清糖组学的细微定量差异方面具有可行性。