糖脂与磷脂自组织体系的相结构及其动态行为研究

Glycolipids and phospholipids are important components of biological membranes. They can form organized structures in a self-assembled manner. It is believed that an understanding of the ordered structures, as well as their dynamic feature, at molecular level will assist to understand the biological functions of membranes. In this NSFC project, a number of basic problems concerning the biophysical chemistry of membranes have been tackled. First, Self-assembled ordered structures formed by glycolipids such as glucocerebroside and phospholipids such as phosphatidycholines and phosphatidylethanolamnes are studied in some detail. It has been found that glucocerebroside can induce the formation of isotropic cubic phases. Liquid ordered phase was also identified in the presence of the glycolipid. Second, the dynamic feature of the phase transitions have been investigated by differential scanning calorimetry and spectroscopic methods. Avrami and Tobin theories were used to describe the kinetics of the phase transitions. A model of the formation of lamellar crystal phase was established. Third, modulation of small cosolute molecules such as dimethyl sulphoxide and on the stability and properties of ordered lipid structures were studied. The different effect of these cosolutes was demonstrated. Fourth, phase behavior of the lipid in monolayers has also been investigated and a new method based on two-dimensional compressibility is established. In order to understand the abundant observations reported, model lipid molecules, such as amine, were used to study selective or competitive molecular interactions. A new method based on the two-dimensional correlation spectroscopy has been established. In addition, basic concept and relations of thermodynamics quantities have also been studied. The conclusion could be applied in systems far beyond the glycolipid-phospholipid systems.

糖脂在生物细胞识别、粘附中起着重要作用。糖脂与磷脂及其它成分聚集成有序结构是它们得以产生协同作用并保证细胞体进行正常新陈代谢的关键。本课题以糖脂和磷脂体系为研究对象，用同步辐射X－光衍射等手段研究这类自聚体的相结构、动态行为，并研究外源凝集睾托》肿游镏识哉庑┬灾实挠跋旃媛桑教志奂迥诤途奂寮涓髦窒嗷プ饔玫谋局省