由或离子结合诱导的Enterococcus hirae的V-ATPase的K环结构变化,由ATR-FTIR光谱学揭示
Yuji Furutani1, Takeshi Murata, Hideki Kandori
1Department of Frontier Materials, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555, Japan.
Journal of the American Chemical Society
|February 16, 2011
概括
维-ATPase酶可以运输和离子. 离子结合会导致关键的结构变化,如Glu139的脱质子化,从而促进了有效的介质体穿过膜的运输.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 膜运输 运输 膜运输
背景情况:
- 来自Enterococcus hirae的V-ATPase是一种大型蛋白质复合体 (∼700,000 MW).
- 它在生理上将Na(+) 和Li(+) 通过脂质二层进行运输.
- 之前的研究依赖于嵌入膜K环域的X射线晶体学.
研究的目的:
- 在生理条件下的完整V-ATPase中研究离子结合诱导的结构变化.
- 阐明特定残留物和构造变化在阴子运输中的作用.
主要方法:
- 测量完整的V-ATPase的离子结合诱导的红外 (IR) 光谱差异.
- 实验是在生理温度下进行的,并且有足够的水分.
主要成果:
- 或离子结合会诱导Glu139.9的去质子化.
- 在氨酸残留物中观察到结变化.
- 在K环结构中检测到轻微的形状变化.
结论:
- Glu139的去质子化对于阴离子运输至关重要.
- 结构变化有助于减少离子转移的能量障碍.
- 这些发现为V-ATPase的阳离子运输机制提供了洞察力.
相关概念视频
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