微纤维素相关的糖蛋白4形成了八合体,它与弹性蛋白和细胞的相互作用中介
Michael R Wozny1, Valentin Nelea1,2, Iram Fatima S Siddiqui1
1Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada.
Nature communications
|May 13, 2024
概括
微纤维相关甘氨蛋白4 (MFAP4) 形成一个八合体结构,其与其他蛋白质和细胞的相互作用至关重要. 对MFAP4的这种结构洞察力是了解其在纤维化和动脉瘤等疾病中的作用的关键.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 细胞外矩阵研究 细胞外矩阵研究
背景情况:
- 微纤维相关糖蛋白4 (MFAP4) 是一种细胞外基质糖蛋白,涉及器官纤维化,COPD和心血管疾病.
- 已确定MFAP4在大动脉动脉瘤中的作用及其与弹性蛋白 (纤维素-1,托波拉斯) 和细胞 (通过整合素) 的相互作用,但其结构细节仍然难以捉摸.
研究的目的:
- 使用冷电子显微镜确定人类MFAP4的三维结构.
- 阐明负责MFAP4与其他蛋白质和细胞组件相互作用的分子接口.
- 研究和二硫化物键在MFAP4组装和功能中的作用.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于获得人类MFAP4.4的高分辨率结构数据.
- 原子模型构建到冷电磁图中,以定义结构特征和相互作用接口.
- 生物化学结合试验用于评估与纤维素-1,托波拉斯,LTBP4和小纤维素的相互作用.
- 位点定向突变发生 (C34S) 研究二硫化键在组装和功能中的作用.
主要成果:
- 冷-EM结构显示,在的存在下,MFAP4组装成一个八度体,由两组同质体组成.
- 同位体被分子间二硫化物键稳定,八位体组合涉及盐桥和非极性相互作用.
- MFAP4表现出多个蛋白质-蛋白质相互作用表面,在很大程度上取决于其八元组合,这些相互作用在很大程度上不受C34S突变的影响.
- 发现MFAP4-纤维素-1组件可以抑制MFAP4与细胞的相互作用.
结论:
- MFAP4八度体的确定的结构为其组装机制和交互接口提供了关键的见解.
- MFAP4的多重体状态对于其多样化的蛋白质-蛋白质相互作用至关重要,影响其在细胞外矩阵组织和细胞信号传递中的生物作用.
- 了解MFAP4的结构功能关系,特别是它与纤维素-1的相互作用,可能为纤维化和心血管疾病提供治疗点.
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