人体IgA和J链上的每个N-甘氨酸都独特地影响了寡合性和稳定性
Shunli Pan1, Noriyoshi Manabe1, Shiho Ohno1
1Division of Structural Glycobiology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Miyagi, Japan.
Biochimica et biophysica acta. General subjects
|December 9, 2023
概括
免疫球蛋白A1 (IgA1) 上的N-甘氨酸对其结构至关重要. 在IgA1-Fc上的N459-甘氨酸对于形成二次体和防止聚合物至关重要,而其他甘氨酸则稳定复合物.
科学领域:
- 免疫学 免疫学 免疫学
- 葡萄糖生物学 葡萄糖生物学
- 结构生物学 结构生物学
背景情况:
- 免疫球蛋白A (IgA) 是粘膜免疫的关键,通常通过J链形成二元体.
- 人类IgA1-Fc有两个N-糖化位,而J链有一个.
- 这些N-糖化酶的功能作用尚不清楚.
研究的目的:
- 研究N-糖化位点在人类IgA1-Fc和J链组合中的功能作用.
- 阐明特定的N-甘氨酸对IgA1分子结构和稳定性的影响.
主要方法:
- 具有和没有J链的IgA1-Fc突变体的表达.
- 质谱测量以确定N-甘氨酸修饰部位.
- 热和光测试以评估复杂的稳定性和分子相互作用.
- 核磁共振分析以确定糖甘的灵活性.
主要成果:
- 在N263 (Fc),N459 (Fc尾部) 和N49 (J链) 的N-糖化位点得到证实.
- IgA1-Fc N459Q突变破坏了二元体的形成,导致了更高阶的聚合物.
- N459-glycans似乎可以防止Fc-Fc相互作用,从而促进适当的二聚体形成.
- N263 (Fc) 和N49 (J链) 甘有助于Fc-J链复合体的热稳定性.
结论:
- 在IgA1-Fc上的N459-glycan对于正确的二元组合和防止聚合至关重要.
- 在N263 (Fc) 和N49 (J链) 的N-甘氨酸在稳定IgA1-Fc-J链复合体方面发挥着不同的作用.
- 这项研究澄清了IgA1分子组织中N-甘氨酸的特定位置功能.
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