Sum-Frequency Vibrational Spectroscopy Study of Membrane Asymmetry and the Transbilayer Movement of Lipids

膜不对称性和脂质跨双层运动的和频振动光谱研究

• 批准号: 0515940
• 负责人: John Conboy
• 金额: $ 37.7万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0515940&HistoricalAwards=false
• 关键词: Sum; Frequency; Vibrational; Spectroscopy; Study

Professor John Conboy of the University of Utah is supported by the Analytical and Surface Chemistry Program to probe the movement of lipid species across cellular membranes by performing non-linear surface specific sum-frequency vibrational spectroscopy measurements on model lipid bilayers. The transbilayer movement of lipid, also known as lipid flip-flop or translocation, is a fundamentally important issue in molecular biology and has attracted interest among biologists and chemists for decades. Typically, lipid flip-flop has been investigated by nuclear magnetic spectroscopy (NMR), electron spin resonance spectroscopy and fluorescence spectroscopic techniques with model membrane systems such as vesicles and planar-supported lipid bilayers. To perform NMR or fluorescence measurements, lipids must be either spin-labeled or fluorescence-labeled. The labeling process will modify lipid physical properties and therefore has been considered as the drawback of these techniques. In this work, the PI is using a novel methodology to investigate lipid transbilayer movement that does not require the labeling. In addition, real-time monitoring of transbilayer movement can be attained. The PI is studying various properties of the flip-flop of perdeuterated lipids in planar membranes such as its activation energy, its dependence on lateral pressure, the effect of lipid structure and of membrane composition. In particular, the influence of cholesterol and selected membrane-active peptides on phospholipid flip-flop is being addressed. New findings drawn from the research could have a significant impact in molecular and cellular biology. Further, taking into account the increasing relevance of supported bilayers in nanotechnology and other fields, the proposal provides a very powerful and original approach to study and to optimize those films for various applications.

犹他大学的 John Conboy 教授在分析和表面化学计划的支持下，通过对模型脂质双层进行非线性表面特定和频振动光谱测量来探测脂质物质跨细胞膜的运动。脂质的跨双层运动，也称为脂质翻转或易位，是分子生物学中的一个根本性重要问题，几十年来引起了生物学家和化学家的兴趣。通常，通过核磁光谱 (NMR)、电子自旋共振光谱和荧光光谱技术以及模型膜系统（例如囊泡和平面支撑的脂质双层）研究脂质触发器。要进行 NMR 或荧光测量，脂质必须经过自旋标记或荧光标记。标记过程会改变脂质的物理性质，因此被认为是这些技术的缺点。在这项工作中，PI 正在使用一种新颖的方法来研究不需要标记的脂质跨双层运动。此外，还可以实现跨双层运动的实时监测。 PI正在研究平面膜中全氘化脂质的触发器的各种特性，例如其活化能、其对侧压力的依赖性、脂质结构和膜组成的影响。特别是，胆固醇和选定的膜活性肽对磷脂触发器的影响正在得到解决。该研究的新发现可能会对分子和细胞生物学产生重大影响。 此外，考虑到支撑双层在纳米技术和其他领域中日益重要的相关性，该提案提供了一种非常强大且原创的方法来研究和优化这些薄膜以适应各种应用。