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Studying Cell Rolling Trajectories on Asymmetric Receptor Patterns
Published on: February 14, 2011
P-选择因-碳水化合物键的寿命及其对水力动力流中的拉力反应
R Alon1, D A Hammer, T A Springer
1Center for Blood Research, Harvard Medical School, Boston, Massachusetts 02115, USA.
Nature
|April 6, 1995
概括
选择素调解白细胞结合和在血管壁上滚动. 它们的快速结合动力学和机械特性,包括0.5 Å的结合相互作用距离,对于在生理剪切应力下进行这一过程至关重要.
科学领域:
- 生物物理学的生物物理.
- 细胞生物学 细胞生物学
- 免疫学 免疫学 免疫学
背景情况:
- 选择素是细胞粘附分子,调解白细胞结合和在血管壁上滚动.
- 这些相互作用对于免疫监测和炎症反应至关重要.
- 建议选择结合的机械特性和动力学可以促进在水力动力学力下滚动.
研究的目的:
- 在水力动力流中可视化和描述中性粒细胞和P-选择因之间的过渡性选择因介导.
- 为了确定P-选择素和PSGL-1相互作用的动力参数和机械特性.
- 为了研究水力动力学切割应力对selectin键解离的影响.
主要方法:
- 视觉化过渡性结合和释放中性粒细胞在脂质双层上的水力动力流中,控制P-选择素密度.
- 在不同的剪切应力下测量P-selectin和PSGL-1键的解离速率常数 (off-rate).
- 应用一个拟议的机械模型来关联离速率,拉力和键相互作用距离.
主要成果:
- 过渡性带表现出第一阶动力学,表明P-选择素和PSGL-1之间的单分子相互作用.
- 无应力解离速率常数 (脱离速率) 确定为1s-1.
- 增加的水力动力切割应力 (高达1.1 动力厘米-2,~110 pN力) 仅适度地增加了偏离率至3.5 s-1.
- 计算出了0.5 Å的键相互作用距离,与和金属协调键一致.
结论:
- P-selectin-PSGL-1相互作用的特点是快速的开/关速率和显著的抗拉强度.
- 键相互作用距离为0.5 Å,表明特定的分子相互作用,可能涉及和金属协调键.
- 这些分子性质对于在生理剪切应力下支持白细胞滚动相互作用至关重要.
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