The phase diagram of the monoolein/water system: metastability and equilibrium aspects
The phase diagram of the monoolein/water system: metastability and equilibrium aspects
复制标题
DOI：
10.1016/s0142-9612(99)00126-x
复制
发表时间：
2000-02-01
期刊：
影响因子：
14
通讯作者：
Caffrey, M
中科院分区：
文献类型：
--
作者：
Qiu, H;Caffrey, M
在最近的过去，在单油酸甘油酯/水系统的液晶结构，运输和膜蛋白质结晶性能的兴趣已经增长。单油酸甘油酯也是一个重要的同系物，在一系列的单酰基甘油用于破译脂质分子结构如何涉及到液晶相行为的合理设计应用和了解膜脂质多样性的起源所需的信息。为了更好地利用单油酸甘油酯/水体系，需要一个可靠而详细的温度-组成相图。Briggs等人（J Phys II France 1996;6：723-51）的相图是为此目的而构建的。然而，我们已经确定，在下文中的后者中的液晶相约为。20摄氏度是亚稳定的。通过在加热方向上收集数据之前实施零度以下（摄氏度）的样品孵育，我们可以将系统重置为层状晶体相，我们假设这代表平衡行为。我们重新研究了低温部分的相图和结构特征的新的“平衡”相静态和时间分辨低和广角X-射线衍射和差示扫描量热法。一个更完整的相图，结合新的平衡行为在低温下的报告。(C)1999爱思唯尔科技有限公司。保留所有权利。
Interest in the liquid crystal structure, transport and membrane protein crystallizing properties of the monoolein/water system has grown in the recent past. Monoolein is also an important homolog in a series of monoacylglycerols used to decipher how lipid molecular structure relates to liquid crystal phase behavior-information needed for rational design applications and for understanding the origin of membrane lipid diversity. To make intelligent use of the monoolein/water system, a reliable and detailed temperature-composition phase diagram is needed. The phase diagram of Briggs et al. (J Phys II France 1996;6:723-51) was constructed for this purpose. However, we have established that the liquid crystal phases in the latter below ca. 20 degrees C are metastable. By implementing a sub-zero degree (degrees C) sample incubation prior to data collection in the heating direction, we can reset the system into the lamellar crystal phase which we assume represents equilibrium behavior. We have re-examined the low-temperature part of the phase diagram and characterized structurally the new 'equilibrium' phases by static and time-resolved low- and wide-angle X-ray diffraction and by differential scanning calorimetry. A more complete phase diagram that incorporates the new equilibrium behavior at low temperatures is reported. (C) 1999 Elsevier Science Ltd. All rights reserved.