拉米宁G域定义了蛋白质S介导因子IXa抑制的关键接口
Rafika Yasmin1, Rima Chattopadhyay1, Vandana1
1Department of Interdisciplinary Oncology, Louisiana State University Health Sciences Center, New Orleans, LA, 70112.
Journal of thrombosis and haemostasis : JTH
|January 8, 2026
概括
蛋白S直接抑制因子IXa,使用其胺G域,独立于其辅因子作用. 这一发现确定了开发向抗血栓治疗的关键结合部位.
科学领域:
- 生物化学 生化学
- 分子生物学分子生物学
- 血液学 血液学 血液学
背景情况:
- 血液静止依赖于促凝和抗凝因素之间的平衡.
- 蛋白S (PS) 是一种依赖维生素K的糖蛋白,参与血液静止.
- PS作为一个辅助因子,直接抑制激活的因子IX (FIXa),但其对FIXa的结合接口是未知的.
研究的目的:
- 确定蛋白S.上的FIXa结合接口.
- 阐明蛋白S的拉米林G (LG) 域在FIXa结合和抑制中的作用.
主要方法:
- 分子对接预测了FIXa-PS绑定接口.
- 基于光的测定量化了结合亲和力.
- 功能凝血试验测量测量了抑制常数.
- 局部定向突变发生产生并测试了PS突变物.
主要成果:
- 蛋白S的LG1和LG2域都与FIXa相互作用.
- 在LG1+2合域显示了对FIXa的最高亲和力 (Kd ≈ 52.15 nM).
- LG1+2域有效抑制了FIXa介导的X因子激活和血栓生成.
- 突变酶在LG域中发现了特定的残留物 (E435,E437),这些残留物对FIXa结合和抑制至关重要.
结论:
- 蛋白S的LG域对于直接FIXa抑制至关重要,与其辅因子功能分开.
- 这项研究为设计选择性FIXa抑制剂提供了结构基础.
- 这些发现支持开发针对FIXa的新型抗血栓策略.
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