在COMP:一个原型离子通道中,一个五链绕式线圈的晶体结构?
V N Malashkevich1, R A Kammerer, V P Efimov
1Department of Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.
概括
软骨的寡合矩阵蛋白质 (COMP) 结构显示出一个稳定的,米绕式卷轴,带有离子结合孔. 这种蛋白质寡合化域与跨膜离子通道有相似之处.
科学领域:
- 结构生物学是结构生物学.
- 蛋白质的生物化学 蛋白质的生物化学
- 细胞外矩阵研究研究.
背景情况:
- 通过α-螺旋捆的蛋白质寡合化是一种基本的生物过程.
- 软骨的寡合基基质蛋白 (COMP) 在细胞外基质中起着至关重要的作用.
研究的目的:
- 为了确定COMP寡合化域的晶体结构.
- 阐明COMP稳定性和功能的结构基础.
- 将COMP的结构与其他相关蛋白质和离子通道进行比较.
主要方法:
- 在2.05安格斯特罗姆分辨率的X射线晶体学.
主要成果:
- 在COMP.中确定了平行米线圈线圈的晶体结构.
- 确定了对热稳定性有助的补充性疏水相互作用和二硫化物桥梁.
- 发现了一个疏水的轴孔,能够结合水和小的无极群.
- 由胺残留物形成的"离子陷"具有特征,它结合了像化物这样的单原子离子.
结论:
- COMP 寡合化域表现出独特的热稳定结构,具有离子结合孔.
- 这种结构与拟议的 pentameric 跨膜离子通道模型有显著的相似之处.
- 这些发现提供了对COMP功能和在其他细胞外矩阵蛋白 (如血栓子蛋白) 中的潜在作用的见解.
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