Profiling of Endo H-released serum N-glycans using CE-LIF and MALDI-TOF-MS - Application to rheumatoid arthritis
Profiling of Endo H-released serum N-glycans using CE-LIF and MALDI-TOF-MS - Application to rheumatoid arthritis
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DOI：
10.1002/elps.201100250
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发表时间：
2011-12-01
期刊：
影响因子：
2.9
通讯作者：
Blanchard, Veronique
中科院分区：
文献类型：
--
作者：
Frisch, Elena;Kaup, Matthias;Blanchard, Veronique
高甘露糖和杂交型N-葡聚糖存在于低丰度的人血清糖蛋白中，但最近被描述为在免疫反应中发挥重要作用。因此，重要的是找到一种战略，在健康和疾病的背景下选择性地分析它们的结构，以便了解它们对疾病机制的影响。我们在此报告了人血清中高甘露糖和杂交型N-糖链的特征。为此，利用内切-β-N-乙酰氨基葡萄糖苷酶H(Endo H)释放N-葡聚糖，并用CE-LIF和MALDI-TOF-MS进行分析。我们发现高甘露糖结构Man59GlcNAc1代表了池的大部分。可鉴定出单糖结构Glc1Man9GlcNAc1和四种杂化结构。然后，我们比较了类风湿关节炎患者和健康对照组的内源性H-释放的血清葡萄糖，因为甘露糖结合凝集素缺乏症(MBL)和α-甘露糖苷酶活性的调节以前与这种疾病相关。有趣的是，我们观察到高甘露糖和杂合结构都相当稳定，这表明循环中的MBL和α-甘露糖苷酶可能不会显著影响携带这些多糖的血清糖蛋白水平。
High-mannose and hybrid-type N-glycans are present in human serum glycoproteins in low abundance but have recently been described to play an important role in immune responses. It is therefore important to find a strategy to selectively analyze their structures in the context of health and disease in order to understand their impact on disease mechanisms. We report here the characterization of high-mannose and hybrid-type N-glycans in total human serum. To this end, N-glycans were released using Endo-beta-N-acetylglucosaminidase H (Endo H) and analyzed by CE-LIF and MALDI-TOF-MS. We found that the high-mannose structures Man59GlcNAc1 represented the majority of the pool. The monoglucosylated structure Glc1Man9GlcNAc1 as well as four hybrid structures could be identified. Then, we compared the Endo H-released serum glycome of patients suffering from rheumatoid arthritis with healthy controls as mannose-binding lectin deficiency (MBL) and modulation of a-mannosidase activity were previously associated with this disease. Interestingly, we observed that both high-mannose and hybrid structures were fairly constant, suggesting that circulating MBL and a-mannosidase may not affect significantly the levels of serum glycoproteins carrying these glycans.