在膜蛋白中通过大多数键侧链相互作用进行了适度的稳定
Nathan Hyunjoong Joh1, Andrew Min, Salem Faham
1Department of Chemistry and Biochemistry, UCLA-DOE Center for Genomics and Proteomics, Molecular Biology Institute, USA.
Nature
|May 27, 2008
概括
膜蛋白中的键比以前想象的要弱,对稳定性贡献很小. 这一发现影响了我们对膜蛋白折叠,动力学和设计的理解.
科学领域:
- 结构生物学是结构生物学.
- 生物物理学的生物物理.
- 膜蛋白研究研究 膜蛋白研究
背景情况:
- 键对于结构生物学中的分子相互作用至关重要.
- 由于其低介电常数和缺乏水竞争,它们被认为在膜环境中很重要.
- 极地残留替代物是膜蛋白中常见的致病突变.
研究的目的:
- 量化测试大型膜蛋白中的键强度.
- 为了研究后中螺旋间侧链键的能量贡献.
- 为了比较膜蛋白中的键特性与可溶性蛋白.
主要方法:
- 双变异性循环分析被用来测量键贡献.
- 在膜蛋白核中对极性原子结合伙伴的分析.
- 在可溶性蛋白和膜蛋白中键长度的统计比较.
主要成果:
- 在bacteriorhodopsin中,八个螺旋间侧链键的平均贡献为0.6 kcal mol ((-1).
- 膜蛋白非极性核心区域中4%的极性原子缺乏键合作伙伴.
- 在膜蛋白和可溶性蛋白中,埋藏的键长度在统计上是相同的.
结论:
- 膜蛋白中的结相互作用只是适度稳定.
- 这些键的弱稳定性应该为研究膜蛋白折叠,动态,设计,进化和功能的研究提供信息.
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