Glycan characterization of pregnancy-specific glycoprotein 1 and its identification as a novel Galectin-1 ligand
Glycan characterization of pregnancy-specific glycoprotein 1 and its identification as a novel Galectin-1 ligand
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DOI：
10.1093/glycob/cwaa034
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发表时间：
2020-11-01
期刊：
影响因子：
4.3
通讯作者：
Dveksler, Gabriela
中科院分区：
文献类型：
--
作者：
Mendoza, Mirian;Lu, Dongli;Dveksler, Gabriela
妊娠特异性β 1糖蛋白（PSG 1）是从人胎盘的滋养层细胞分泌的，随着妊娠的进展，其浓度逐渐增加，成为妊娠晚期母体血清中最丰富的蛋白质之一。PSG 1在其四个结构域中具有七个潜在的N-连接糖基化位点。我们进行了糖组学和糖蛋白质组学研究，以表征从孕妇血清中纯化的PSG 1的聚糖组成，并鉴定了含有在四个位点具有α 2，3唾液酸化的聚LacNAc表位的复杂N-聚糖的存在。使用不同的技术，我们探索了PSG 1是否可以与半乳糖凝集素1（Gal-1）结合，因为这两种蛋白质先前已被证明参与成功怀孕所需的过程。我们证实，PSG 1结合Gal-1的碳水化合物依赖性的方式与0.13 μ M的相互作用的亲和力。此外，我们确定了三个N-糖基化携带域，只有N和A2域的重组PSG 1与Gal-1相互作用。最后，我们观察到PSG 1和Gal-1之间的相互作用保护这种凝集素免受氧化失活，并且PSG 1与Gal-1竞争结合其部分但非全部糖蛋白配体的能力。
Pregnancy-specific beta 1 glycoprotein (PSG1) is secreted from trophoblast cells of the human placenta in increasing concentrations as pregnancy progresses, becoming one of the most abundant proteins in maternal serum in the third trimester. PSG1 has seven potential N-linked glycosylation sites across its four domains. We carried out glycomic and glycoproteomic studies to characterize the glycan composition of PSG1 purified from serum of pregnant women and identified the presence of complex N-glycans containing poly LacNAc epitopes with alpha 2,3 sialyation at four sites. Using different techniques, we explored whether PSG1 can bind to galectin-1 (Gal-1) as these two proteins were previously shown to participate in processes required for a successful pregnancy. We confirmed that PSG1 binds to Gal-1 in a carbohydrate-dependent manner with an affinity of the interaction of 0.13 mu M. In addition, we determined that out of the three N-glycosylation-carrying domains, only the N and A2 domains of recombinant PSG1 interact with Gal-1. Lastly, we observed that the interaction between PSG1 and Gal-1 protects this lectin from oxidative inactivation and that PSG1 competes the ability of Gal-1 to bind to some but not all of its glycoprotein ligands.