通过偏磁性NMR观察到的阿波麦芽糖结合蛋白的开放到闭合过渡
Chun Tang1, Charles D Schwieters, G Marius Clore
1Laboratory of Chemical Physics, Building 5, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, USA.
Nature
|October 26, 2007
概括
马尔托结合蛋白 (MBP) 的阿波状态存在于开放和封闭形式的动态混合物中,而不是单一的开放物种. 这一发现揭示了影响蛋白质功能的快速平衡.
科学领域:
- 蛋白质动态和结构变化
- 生物物理和结构生物学
- 酶动力学和酶调节
背景情况:
- 蛋白质经历了对功能至关重要的大规模域重组.
- 晶体结构提供了ap (开放) 和hol (关闭) 蛋白质状态的静态快照.
- 在平衡状态下,不同的类物种的存在仍然不清楚.
研究的目的:
- 为了研究马尔托结合蛋白 (MBP) 的阿波状态的结构动力学.
- 为了确定异种状态是否存在于单一物种或符合性物种的混合物中.
- 为了描述任何存在的小类动物的结构.
主要方法:
- 利用了偏磁放松增强 (PRE) 数据来研究apo MBP.
- 根据PRE数据应用集体模拟回火精炼.
- 将PRE数据与apo和holo MBP的现有晶体结构进行比较.
主要成果:
- 整体MBP的PRE数据与晶体结构一致.
- 对于apo MBP的PRE数据表明,在主导的开放形式 (~95%) 和较小的封闭形式 (~5%) 之间发生了快速交换 (ns-μs).
- 确定了较小的阿波物种独特的整体平均结构,与全息状态不同.
结论:
- MBP的apo状态不是单一的物种,而是一个动态的平衡.
- 一个小的,部分封闭的apo conform存在于与占主导地位的开放形式的快速交换中.
- 这种形状灵活性可能在带结合和蛋白质调节中起作用.
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