Monitoring detergent-mediated solubilization and reconstitution of lipid membranes by isothermal titration calorimetry
Monitoring detergent-mediated solubilization and reconstitution of lipid membranes by isothermal titration calorimetry
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DOI：
10.1038/nprot.2009.35
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发表时间：
2009-01-01
期刊：
影响因子：
14.8
通讯作者：
Keller, Sandro
中科院分区：
文献类型：
--
作者：
Heerklotz, Heiko;Tsamaloukas, Alekos D.;Keller, Sandro
通过洗涤剂和具有洗涤剂样性质的生物分子对生物或脂质体膜的溶解和重构在技术应用中起着重要作用（例如，例如，在一个实施例中，膜蛋白的分离）和生物现象（例如，例如，在一个实施例中，两亲肽）。因此，重要的是要知道和理解膜溶解的开始和完成所需的给定去污剂的量以及通常的去污剂-脂质相互作用。脂质-去污剂系统可以形成多种聚集体结构，其可以被分组为两个假相（层状和胶束），使得增溶可以近似地描述为相变。在这里，我们提出了一个协议，建立相图和详细的热力学描述的脂质洗涤剂系统的基础上等温滴定量热法（ITC）。该协议也可用于检测添加剂诱导的膜去稳定化，透化，域的形成和脂质依赖性的棒状和球形胶束之间的转换。由所有样品制备程序和单个增溶实验组成的最小方案可在2天内完成;包括增溶和复溶实验的更广泛系列需要数天至数周，具体取决于进行的滴定次数。
The solubilization and reconstitution of biological or liposomal membranes by detergents and biomolecules with detergent-like properties play a major role for technical applications (e. g., the isolation of membrane proteins) and biological phenomena (of, e. g., amphiphilic peptides). It is therefore important to know and understand the amounts of a given detergent required for the onset and completion of membrane solubilization and the detergent-lipid interactions in general. Lipid-detergent systems can form a variety of aggregate structures, which can be grouped into two pseudophases (lamellae and micelles) so that solubilization can be approximately described as a phase transition. Here we present a protocol for establishing the phase diagram and a detailed thermodynamic description of a lipid-detergent system based on isothermal titration calorimetry (ITC). The protocol can also be used to detect additive-induced membrane destabilization, permeabilization, domain formation and lipid-dependent transitions between rod-like and spherical micelles. A minimal protocol consisting of all sample preparation procedures and a single solubilization experiment can be accomplished within 2 days; a more extensive series comprising both solubilization and reconstitution experiments requires several days to a few weeks, depending on the number of titrations performed.