PHOSPHOLIPID VESICLES--MODEL FOR BIOLOGICAL MEMBRANES

磷脂囊泡——生物膜模型

• 批准号: 2172412
• 负责人: CHING-HSIEN HUANG
• 金额: $ 20.06万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 1977
• 资助国家: 美国
• 起止时间: 1977-05-01 至 1996-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2172412
• 关键词: Raman spectrometry; X ray crystallography; acyl group; calorimetry; chemical chain length; chemical hydration; chemical synthesis; fatty acylation; gel; gel filtration chromatography; hydropathy; intermolecular interaction; lipid bilayer membrane; lipid structure; liquid crystal; lysolecithins; membrane lipids; membrane structure; methyl group; micelles; molecular asymmetry; nuclear magnetic resonance spectroscopy; phase change; phosphatidylcholines; phosphatidylethanolamines; phosphoglycerides; stereochemistry; temperature; thermodynamics

The long-term objective of this research project is an in-depth investigation of the thermodynamic and structural properties of various chemically well-defined mixed-chain phospholipids in lipid bilayers. It has long been established that phospholipids are a major class of lipid components in the highly complex organization of biological membranes and that phospholipids isolated from biological membranes are typically of the mixed-chain variety, meaning that the two hydrocarbon chains are different in both the chemical structure and the physical strength. Our proposed studies of mixed-chain phospholipids may, therefore, have important structural and functional relevance in understanding the physical and biological nature of biological membranes. Specifically, the proposed five-year research is designed along the following lines: (1) Recently we have applied high-resolution differential scanning calorimetry (DSC), vibrational spectroscopy, 31P NMR, and X-ray diffraction to investigate the thermodynamic and structural properties of various mixed-chain phosphatidylcholines (PC) in the bilayer. We shall continue our investigation but concentrating on the most highly asymmetric PC. (2) Both the packing effect and the hydrophobic hydration may contribute to the unusually large transition enthalpy (deltaH) and entropy (deltaS) associated with the phase transition involving the mixed interdigitated bilayer. We shall determine which one of the two effects is more important. (3) We shall construct phase diagrams for binary phospholipid mixtures and to obtain quantitative information regarding the lipid-lipid interactions by simulating the shape of the phase diagram using a computer program developed in this laboratory. (4) The thermotropic phase behavior and structural properties of mixed-chain PE and their headgroup derivatives will be studied systematically. (5) Empirical predictions of the main phase transition temperatures (Tm) for mixed-chain phospholipids (PC, PE and derivatives) will be developed. (6) We shall examine the thermotropic phase behavior of two series of mixed-chain phosphatidylglycerol (PG) with molecular weights identical with C(16):C(16)PG and C(14):C(14)PG, respectively. The results of the research proposed in this project will add a new dimension to our current knowledge about the structure and properties of membrane lipids.

该研究项目的长期目标是深入 调查各种热力学和结构特性 脂质双层中化学定义明确的混合链磷脂。 它 长期以来已经确定磷脂是一类主要的脂质 高度复杂的生物膜组织中的组成部分 从生物膜中分离出的磷脂通常是 混合链品种，这意味着两个烃链是 化学结构和物理强度都不同。 我们的 因此，对混合链磷脂的拟议研究可能具有 重要的结构和功能相关性 生物膜的物理和生物学性质。 具体来说， 拟议的五年研究按以下几行设计： （1）最近我们应用了高分辨率差异扫描 量热法（DSC），振动光谱，31p NMR和X射线 研究热力学和结构特性的衍射 双层中各种混合链磷脂酰胆碱（PC） 我们 应继续我们的调查，但专注于最高的 不对称PC。 （2）包装效果和疏水性水合 可能有助于异常大的过渡焓（Deltah）和 熵（三角洲）与相关相关的相关 混合互插的双层。 我们将确定两者中的哪一个 效果更重要。 （3）我们将构建相图 二元磷脂混合物并获得定量信息 通过模拟脂质脂质相互作用 使用本实验室开发的计算机程序的相图。 （4） 混合链的热相行为和结构特性 PE及其头组衍生物将被系统地研究。 （5） 主相过渡温度（TM）的经验预测 将开发混合链磷脂（PC，PE和衍生物）。 （6）我们将检查两个系列的热相位行为 分子量相同的混合链磷脂酰甘油（PG） 与C（16）：C（16）Pg和C（14）：C（14）Pg。 结果 该项目提出的研究将为我们的 有关膜脂质的结构和特性的当前知识。