NHC Key Laboratory of Transplant Engineering and Immunology, Institutes for Systems Genetics; National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, China.
Sichuan Provincial Engineering Laboratory of Pathology in Clinical Application, West China Hospital, Sichuan University, Chengdu 610041, China.
Analyst. 2021 Nov 22;146(23):7274-7283. doi: 10.1039/d1an01657a.
Immunoglobulin G (IgG) molecules modulate an immune response. However, site-specific -glycosylation signatures of plasma IgG in patients with chronic kidney disease (CKD) remain unclear. This study aimed to propose a novel method to explore the -glycosylation pattern of IgG and to compare it with reported methods. We separated human plasma IgG from 58 healthy controls (HC) and 111 patients with CKD. Purified IgG molecules were digested by trypsin. Tryptic peptides without enrichment of intact -glycopeptides were analyzed using a combination of electron-transfer/higher-energy collisional dissociation (EThcD) and stepped collision energy/higher-energy collisional dissociation (sceHCD) mass spectrometry (EThcD-sceHCD-MS/MS). This resulted in higher spectral quality, more informative fragment ions, higher Byonic score, and nearly twice the depth of intact -glycopeptide identification than sceHCD or EThcD alone. Site-specific -glycosylation mapping revealed that intact -glycopeptides were differentially expressed in HC and CKD patients; thus, it can be a diagnostic tool. This study provides a method for the determination of glycosylation patterns in CKD and a framework for understanding the role of IgG in the pathophysiology of CKD. Data are available ProteomeXchange with identifier PXD027174.
免疫球蛋白 G（IgG）分子调节免疫反应。然而，慢性肾脏病（CKD）患者血浆 IgG 的位点特异性糖基化特征尚不清楚。本研究旨在提出一种新方法来探索 IgG 的糖基化模式，并将其与已报道的方法进行比较。我们从 58 名健康对照（HC）和 111 名 CKD 患者中分离人血浆 IgG。用胰蛋白酶消化纯化的 IgG 分子。未富集完整糖肽的胰酶肽用电子转移/更高碰撞能解离（EThcD）和分步碰撞能/更高碰撞能解离（sceHCD）质谱（EThcD-sceHCD-MS/MS）组合进行分析。这导致更高的谱质量、更多信息丰富的片段离子、更高的 Byonic 评分，以及完整糖肽鉴定的深度几乎是 sceHCD 或 EThcD 单独使用的两倍。位点特异性糖基化图谱显示，完整糖肽在 HC 和 CKD 患者中存在差异表达；因此，它可以作为一种诊断工具。本研究提供了一种用于确定 CKD 中糖基化模式的方法，并为理解 IgG 在 CKD 病理生理学中的作用提供了一个框架。数据可在 ProteomeXchange 上获取，标识符为 PXD027174。
