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Monitoring Protein Adsorption with Solid-state Nanopores
Published on: December 2, 2011
酸盐介导的氨酸插入脂质膜,并由固态NMR的阴离子膜质形成毛孔
Ming Tang1, Alan J Waring, Mei Hong
1Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
Journal of the American Chemical Society
|August 21, 2007
概括
带电的残留物通过瓜尼尼-酸盐相互作用插入脂质双层,形成状孔隙. 这种在抗微生物中观察到的机制涉及阴性氨酸残留物将阴性酸盐拉入膜核心.
科学领域:
- 生物物理学的生物物理.
- 膜生物物理学 膜生物物理学
- 生物化学 生物化学
背景情况:
- 疏水性脂质双层中的带电氨基酸残留在能量上是不利的.
- 阴离子膜和蛋白质域经常将带电的残留物插入脂质双层.
- 在脂质二层中带电残留物转移的机制尚不清楚.
研究的目的:
- 为了阐明带电残留物跨脂质双层转移的机制.
- 为了研究氨酸丰富的和脂质膜之间的相互作用.
- 为形成状孔提供直接证据.
主要方法:
- 固态核磁共振 (NMR) 谱学用于测量 (13) C-(31) P 距离.
- 扭矩角度测量以确认形状.
- 凝阶段 (1) H 旋转扩散,以评估体在膜内的位置.
主要成果:
- 在脂质膜内的中测量了多个氨酸残留的短距离 (13C-(31) P (4.0-8.0 A).
- 有证据表明,阿尔金因和酸盐组之间形成N-H...O-P键.
- 确认该的跨膜β-毛形状.
- 直接证据表明状孔形成,其中脂质酸盐组嵌入了疏水膜核心.
结论:
- 瓜尼尼-酸盐复合驱动着化氨酸残留物插入到疏水膜核心.
- 这种酸盐介导的瓜尼离子转位是 toroidal 孔形成的关键机制.
- 这些发现表明,这种机制与其他富含氨酸的抗微生物和阴离子膜蛋白有关.
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