在缺少脂膜的情况下,快速有序地通过Hopsarin D分裂前热血素
Fatma Işık Üstok1, Ty E Adams1, James A Huntington1
1Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom.
蛇毒中的hopsarin D (HopD) 强烈地与人类的Va因子和V因子结合,迅速激活没有脂的前列血. 这种毒因子绕过了正常的凝血要求,为蛇毒机制提供了洞察力.
科学领域:
- 生物化学 生物化学
- 毒理学 毒理学 毒理学
- 分子生物学分子生物学
背景情况:
- 血生成依赖于脂膜上的前血酶复合体 (XA因子和Va因子).
- 类蛇毒中含有XA因子和Va因子的正系因子,可引起凝血病.
- 霍普萨林D (HopD) 是来自Hoplocephalus stephensii毒素的XA因子正方体.
研究的目的:
- 为了研究HopD与人体Va因子的结合亲和力.没有脂.
- 为了确定HopD是否通过半热血红素路径对前热血红素进行处理.
- 评估分离顺序的脂依赖性和HopD激活V因子的能力.
主要方法:
- 生产和表征全长和截断的霍普萨林D.
主要成果:
- 与XA因子不同的是,HopD对人类的Va因子和V因子都表现出高亲和度的结合 (∼10nM解离常数),与XA因子不同.
- 不管脂是否存在,HopD通过热血素路径处理前热血素.
- 通过HopD处理原血红素需要V因子转化为Va因子,HopD激活V因子以启动猎物凝血.
结论:
- 在没有脂质的情况下,HopD以高亲和力结合Va因子,并通过中位热血素中间体,完全通过中位热血素迅速激活前热血素.
- 对Va因子和V因子的高亲和结合表明B域在抑制生产性相互作用中的作用,而不是对Xa因子结合的固态阻断.
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