ICAM-2的晶体结构显示出一个独特的整合素识别表面
J M Casasnovas1, T A Springer, J H Liu
1The Center for Blood Research, Harvard Medical School, Department of Pathology, Boston, Massachusetts 02115, USA.
Nature
|May 15, 1997
概括
细胞间粘附分子-2 (ICAM-2) 的晶体结构揭示了整合素与没有整合素的关键差异.
科学领域:
- 细胞粘附 细胞粘附
- 结构生物学是结构生物学.
- 免疫学 免疫学 免疫学
背景情况:
- 集成蛋白调解细胞-细胞和细胞-细胞外基质相互作用.
- 已知的整合素连接体结构 (纤维蛋白,VCAM-1) 涉及缺乏"I"域的整合素.
- 细胞间粘附分子 (ICAMs) 是由含有整体的"I"域识别的,如淋巴细胞功能相关抗原1 (LFA-1).
研究的目的:
- 确定ICAM-2细胞外区域的晶体结构.
- 阐明ICAM-2的LFA-1认可的结构基础.
- 为了比较"I"域含有和"I"域缺乏整合-连接体相互作用之间的识别站点架构.
主要方法:
- 进行X射线晶体学以确定ICAM-2的三维结构.
- 结构分析以确定与LFA-1结合有关的关键残留物和特征.
- 基于ICAM-2结构的ICAM-1的比较结构建模.
主要成果:
- 确定了ICAM-2细胞外区域的晶体结构.
- 谷氨酸在ICAM-2中的位置37 (Glu 37) 对LFA-1结合至关重要,并且可以协调LFA-1"I"域中的Mg2+离子.
- ICAM-2具有相对平坦的识别表面,其中Glu 37在β链中,与纤维蛋白和VCAM-1中突出的循环形成鲜明对比.
结论:
- 在具有和没有"I"域的整体之间存在识别站点的结构差异.
- 在ICAM-2域和N-链 glycans之间的曲可能会促进 LFA-1 的结合.
- ICAM-2结构为了解ICAM-1识别和潜在的病原体相互作用提供了一个模型.
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