Simultaneous characterization of SNPs and N-glycans from multiple glycosylation sites of intact β-2-glycoprotein-1 (B2GP1) by ESI-qTOF-MS
Simultaneous characterization of SNPs and N-glycans from multiple glycosylation sites of intact β-2-glycoprotein-1 (B2GP1) by ESI-qTOF-MS
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DOI：
10.1016/j.bbapap.2019.03.007
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发表时间：
2019-06-01
影响因子：
3.2
通讯作者：
Meyer, Bernd
中科院分区：
文献类型：
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作者：
Baerenfaenger, Melissa;Meyer, Bernd
高度糖基化的β-2-糖蛋白-1（B2 GP 1），也称为载脂蛋白H，是一种50 kDa的人血浆蛋白，具有4或5个N-糖基化位点。B2 GP 1的糖基化可以影响自身抗体识别，导致抗磷脂综合征（APS）的发展，这可能导致流产或血栓形成。除了其糖基化之外，已知不同的遗传变异会增加患APS的风险。在这里，我们表明，完整的B2 GP 1的ESI-q/TOF-MS可用于同时分析遗传变异和糖基化。在富集来自16个不同血浆样品的B2 GP 1和随后的完整蛋白质的ESI-MS测量之后，我们在我们的样品中检测到五种不同的SNP，无论是纯合的还是杂合的。主要聚糖组成显示四种双触角、完全唾液酸化聚糖结构，相对比例约为30%。我们还检测到具有较低量的一个或两个三触角聚糖结构的组合物和具有一个或两个岩藻糖基残基的岩藻糖基化物质。我们的两个样品显示了未报告的部分占据的第五糖基化位点，推测是由SNP变体588 N的存在引起的。我们的方法允许快速确定人B2 GP 1的遗传变异和聚糖组成，可能用作诊断标志物。
The highly glycosylated beta-2-glycoprotein-1 (B2GP1), also called apolipoprotein H, is a 50 kDa human plasma protein with four or five N-glycosylation sites. Glycosylation of B2GP1 can impact auto antibody recognition leading to the development of antiphospholipid syndrome (APS), which can result in miscarriages or thrombosis. Next to its glycosylation different genetic variants are known to increase the risk of suffering from APS. Here we show that ESI-q/TOF-MS of intact B2GP1 can be used to analyze genetic variants and glycosylation simultaneously. After enrichment of B2GP1 from 16 different plasma samples and subsequent ESI-MS measurement of the intact protein, we detected five different SNPs in our samples either homozygous or heterozygous. The dominant glycan composition shows four biantennary, fully sialylated glycan structures, with a relative proportion of about 30%. We also detected compositions with one or two triantennary glycan structures in lower amounts and fucosylated species with one or two fucosyl residues. Two of our samples showed an unreported partially occupied fifth glycosylation site presumably arising from the presence of SNP variant 588N. Our method allows a fast determination of genetic variants and glycan compositions of human B2GP1 to be potentially used as diagnostic marker.