用二维红外光谱测量平面脂多层模型细胞膜内的超快速结构动力学
Oksana Kel1, Amr Tamimi, Megan C Thielges
1Department of Chemistry, Stanford University, Stanford, California 94305, USA.
Journal of the American Chemical Society
|July 11, 2013
概括
这项研究通过2D红外光谱来研究脂质双层动态,发现水化水平不会影响膜内部动态. 然而,胆固醇含量大大改变了膜结构和动态,在35%胆固醇下观察到显著的变化.
科学领域:
- 生物物理学的生物物理.
- 物理化学 物理化学
- 频谱学是一种光谱学.
背景情况:
- 脂质双层形成细胞膜,它们的内部动态对于功能至关重要.
- 了解水分和胆固醇如何影响膜结构和动态是细胞生物学的关键.
研究的目的:
- 用二维红外振动回声光谱来研究脂质二层内的超快速动态.
- 为了确定水分水平和胆固醇含量对1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) 膜的内部动态的影响.
主要方法:
- 使用 2D IR 振动回声光谱来探测 DLPC 多人居室中的超快动态 (200 fs 到 200 ps).
- 使用六碳 (W(CO) 6),作为位于膜的基内部的非极性探针.
- 进行FT-IR研究以分析脂质双层和模型液体的结构变化.
主要成果:
- 水水平 (2-16个水分子) 并没有显著改变内部膜动态,尽管FT-IR表明了一些探头分区.
- 胆固醇含量诱导了结构变化,在35%胆固醇下观察到膜动态的显著突然转变.
- 膜动态从10%到35%的胆固醇保持不变,然后显著放缓并从35%到60%的胆固醇停滞不前.
结论:
- DLPC的内部膜动态对水合水平不敏感.
- 胆固醇在调节脂质双层结构和动态方面发挥着关键作用,明显的过渡发生在35%度左右.
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