古典补充级联的表面激活的结构基础是短素C反应蛋白的表面激活
Dylan P Noone1, Marjolein M E Isendoorn2, Sebastiaan M W R Hamers1
1Department of Cell and Chemical Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
概括
人类C反应蛋白 (CRP) 通过结合胆联体来调节自身免疫力. 它的结构揭示了与C1复合体相互作用的新型矩形平台,为补充系统调节提供了洞察力.
科学领域:
- 免疫学 免疫学 免疫学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- 人类C反应性蛋白 (CRP) 是一个关键的免疫防御 pentamer 参与自身免疫.
- CRP针对自身免疫和心血管疾病,但其激活C1复合体的机制尚不清楚.
- 了解CRP-C1相互作用对于治疗策略至关重要.
研究的目的:
- 确定与C1复合体和胆 (PC) 连接体结合的CRP的结构.
- 阐明CRP激活补充系统的机制.
- 为免疫和自身免疫中CRP介导的补充调节提供结构基础.
主要方法:
- 使用冷电子断层扫描 (cryoET) 和亚断层图片平均值来确定结构.
- 合成的PC模原体被合成,以创建用于CRP结合的细胞模拟脂质体表面.
- 进行了CRP的结构导向突变发生,以产生用于结构研究的活性复合物.
主要成果:
- 获得了CRP结合PC配体和C1复合物的冷ET结构.
- 从四个CRP五体中,CRP形成了独特的矩形平台,结合了四个C1头组.
- 确定了CRP的横向关联残留物,解释了以前的突变发生的数据.
结论:
- CRP使用一种新的矩形平台机制来绑定和调节C1复合体.
- 这种机制不同于抗体Fc介导激活,提供对补体激活的特定控制.
- 这些发现提供了对CRP在先天免疫和自身免疫中的作用的机制性理解.
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