蛋白质配体和细胞质无机离子之间对金属阴离子的竞争:DFT/CDM研究
1Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan.
Journal of the American Chemical Society
|August 10, 2006
概括
尽管有竞争性离子,但细胞金属离子与蛋白质结合,因为蛋白质结合部位在能量上有利,并利用多种相互作用. 碳酸盐基团保护金属结合的连接体免受无机离子的取代.
科学领域:
- 生物化学 生化学
- 计算化学计算化学
- 细胞生物学 细胞生物学
背景情况:
- 化物和酸盐等细胞内离子对细胞功能至关重要.
- 金属酸 (例如Na+,K+,Mg2+,Ca2+) 与蛋白质和核酸结合.
- 了解离子-离子-蛋白相互作用对于细胞生理学至关重要.
研究的目的:
- 阐明控制细胞内离子和蛋白质残留物之间的竞争的物理原理,用于金属阴离子结合.
- 在拥挤的细胞环境中确定影响金属离子选择性的因素.
主要方法:
- 密度函数理论 (DFT) 的计算.
- 连续介电法用于溶解效应.
- 结合自由能量和连接体相互作用的分析.
主要成果:
- 由于蛋白质碳酸盐与无机离子相比,溶解成本较低,金属离子优先与蛋白质结合.
- 蛋白质结合部位作为多牙联体起作用,增强了离子亲和力.
- 阳离子的无水化能量,蛋白质腔电荷和溶剂暴露决定了竞争结果.
结论:
- 蛋白质碳酸基团起着双重作用:高 afinity 金属结合和保护对离子位移.
- 细胞离子不容易将金属离子从它们的蛋白质结合部位中脱离.
- 蛋白质腔和阳离子的物理化学性质决定了金属阴离子竞争的动态.
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