【作者】 王娟；

【导师】 孙润广；

【作者基本信息】 陕西师范大学 ， 生物物理学， 2013， 硕士

【摘要】 生物膜是主要由脂类、糖类和蛋白质构成的超分子体系,对生物细胞能量转换、物质运送、信息识别与传递等生命过程即为重要。研究生物膜的结构和特性不仅具有生物学意义,也为某些疾病的临床治疗提供参考依据。而体外模拟生物膜是研究膜上脂与脂相互作用、脂与膜蛋白相互作用以及膜的结构与特性的重要途径之一。本文主要研究了以下两方面内容：(1)三元混合脂单层热力学特性：在室温下,不同比例的胆固醇与三种比例的磷脂酰胆碱/磷脂酰乙醇胺(2：1,1：1,1：2)分别形成三元混合体系超分子结构,从物理化学的角度分析了三元脂单分子层的混合性及稳定性,并且用原子力显微镜观察单层膜的表观形貌。研究不同比例胆固醇对二元脂单层体系的影响,以及在不同表面压力下混合体系分子间所表现的主要相互作用。(2)膜蛋白-脂单层相互作用：碱性磷酸酶是一种在质膜上分布广泛的酶类膜蛋白,本文探究了碱性磷酸酶与饱和脂肪酸鞘磷脂单层膜的相互作用。用高离子浓度将碱性磷酸酶从亚相中诱导在空气-水界面上,使其与磷脂分子充分作用,形成混合单分子层。比较了单一鞘磷脂单层与碱性磷酸酶/鞘磷脂混合单层的π-A曲线、π-t曲线以及弹性模量,表明,碱性磷酸酶使得单层膜出现一段相变区域,从液态扩张相变为液态扩张/凝聚共存相；碱性磷酸酶的加入对脂单层的稳定性影响不大。通过计算极限分子面积以及原子力高度分析,认为碱性磷酸酶在界面上先以至少10个单分子聚集成簇,再与脂单分子层结合在一起形成混合单层。更多还原

【Abstract】 Biomembrane is a supermolecule system consisted of lipid、protein and saccharide, which is significant in many vital processes,such as the energy transformation of cells、substance transportation、signal identificaton and transduction. Thus, the investigation of biomembrane characheristic is of great significance in biology, also, can provide with information for the preparation of target drug and clinicalcare. Langmuir film is one of the most efficiency models used to investigate the membranes.In this paper, we have researched raft proteins and lipids interactions in two respects:(1) Thermodynamic Study on the mixed Monolayer:Different Choi-content and PE/PC(2:1,1:1,1:2) formed a supermolecule system, the compressibility and stability of which were analysed from the perspective of physical chemistry and the surface of which was observed by atomic force microscopy. It has been researched that the effect different Choi-content on PE/PC mixed monolayers and the interaction between the lipid molecules.(2)Interaction between the proteins and lipid monolayers:Mammalian alkaline phosphatases are widely distributed enzymes on the outer of the plasma membrane. In this work, the interaction between alkaline phosphatases and sphingomylin monolayers.Using the ionic strength to induce alkaline phosphatase on the interface, the mixed alkaline phosphatase/sphingomylin monolayers were studied onto air-buffer surface. From the surface pressure-area per molecule isotherms, the surface pressure-time curves and the surface compressional modulus of pure sphingomylin or mixed monolayers, we have obtained some results. The stransition from a liquid-expanded phase to the liquid-expanded/liquid-condensed coexist phase exists on the isotherm for the mixed monolayers. And the addition of proteins has little influence to the stability of the monolayer. It has been shown that more than10of alkaline phosphatase molecules were clustered as a unit and than combined with sphingomylin to form the monolayer, according to the limiting molecular area and the height analysis.更多还原