在膜界面的维生素-K驱动的γ-碳素化分子基础
Qing Cao1, Aaron Ammerman1, Mierxiati Saimi1
1Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St Louis, MO, USA.
Nature
|January 29, 2025
概括
对于蛋白质功能和疾病治疗至关重要的维生素K依赖的γ-碳酸酶被g-碳酸酶 (VKGC) 催化. 结构研究显示,
科学领域:
- 生物化学
- 结构生物学
- 分子酶学
背景情况:
- 在Ca2+介导的蛋白质复合体组合中, γ- 碳氧化谷氨酸残留是必不可少的,影响血液静止,平衡,免疫反应和内分泌调节.
- 维生素K氨酸 (KH2) 是g- 碳氧化的一个关键辅因子,该过程对于治疗出血和血栓塞栓性疾病至关重要.
研究的目的:
- 阐明人类γ-炭酸酶 (VKGC) 在催化维生素K依赖的γ-炭酸酶中的分子机制.
- 确定基质识别,激活和VKGC的催化过程的结构基础.
主要方法:
- 用冷电子显微镜 (cryo-EM) 来获得人体VKGC的高分辨率结构.
- 确定无结合状态的结构,与KH2,以及不同碳化状态的各种基底蛋白.
- 进行广泛的功能实验以验证结构发现和机制假设.
主要成果:
- 通过与的旋和孔相互作用,VKGC识别了基底蛋白,在受控的腔室内定位富含谷氨酸的域进行化.
- 的结合会导致整体形状的变化,信号VKGC的激活.
- VKGC通过连续脱和KH2环氧化产生强的离子 (超基),促进CO2添加的γ-碳脱.
- 一个密封的疏水道引导超基,通过膜接口将KH2环氧化与γ-碳氧化合.
结论:
- 结构和功能洞察力揭示了VKGC介导的γ-碳氧化过程的复杂机制.
- 这些发现有助于了解膜酶学和维生素K依赖的修饰.
- 这项工作为开发与g-carboxylation相关疾病的新疗法提供了基础.
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