Kinetics of the main phase transition of hydrated lecithin monitored by real-time X-ray diffraction.
Kinetics of the main phase transition of hydrated lecithin monitored by real-time X-ray diffraction.
复制标题
通过实时 X 射线衍射监测水合卵磷脂主要相变的动力学。
DOI：
10.1016/s0006-3495(84)84201-0
复制
发表时间：
1984
影响因子：
3.4
通讯作者：
Bilderback,DH
中科院分区：
文献类型：
--
作者：
Caffrey,M;Bilderback,DH
描述了一种用于观察和记录来自未取向的水合膜脂质二棕榈酰磷脂酰胆碱（DPPC）通过其热致凝胶/液晶相变的实时X射线衍射的方法。来自Cornell高能同步辐射源（Ithaca，纽约）的同步辐射被用作极高亮度的X射线源，并且衍射图像的动态显示使用耦合到外部荧光屏的三级图像增强管来实现。在输出磷光体上的图像足够强，以电影方式记录，并使用光导摄像管相机以30帧X s 1显示在电视监视器上。这些测量设定了2秒的上限的DPPC凝胶-液晶相变，并表明该过渡是一个两态过程。实时方法将X射线衍射作为结构探针的能力与跟踪结构变化动力学的能力相结合。该方法不需要外源性探针，是相对无干扰的，并且可以用于各种物理状态下的膜和不稳定的样品。与静态测量方法相比，该方法具有额外的优势，因为它更有可能检测到瞬时稳定的中间体（如果存在）。
A method is described for observing and recording in real-time x-ray diffraction from an unoriented hydrated membrane lipid, dipalmitoylphosphatidylcholine (DPPC), through its thermotropic gel/liquid crystal phase transition. Synchrotron radiation from the Cornell High Energy Synchrotron Source (Ithaca, New York) was used as an x-ray source of extremely high brilliance and the dynamic display of the diffraction image was effected using a three-stage image intensifier tube coupled to an external fluorescent screen. The image on the output phosphor was sufficiently intense to be recorded cinematographically and to be displayed on a television monitor using a vidicon camera at 30 frames X s1. These measurements set an upper limit of 2 s on the DPPC gel----liquid crystal phase transition and indicate that the transition is a two-state process. The real-time method couples the power of x-ray diffraction as a structural probe with the ability to follow kinetics of structural changes. The method does not require an exogenous probe, is relatively nonperturbing, and can be used with membranes in a variety of physical states and with unstable samples. The method has the additional advantage over its static measurement counterpart in that it is more likely to detect transiently stable intermediates if present.