LIPID CONTROL OF MEMBRANE PROTEIN ORGANIZATION

膜蛋白组织的脂质控制

• 批准号: 6240273
• 负责人: RICHARD MENDELSOHN
• 金额: $ 2.51万
• 依托单位: RUTGERS THE STATE UNIV OF NJ NEWARK
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6240273
• 关键词: CD2 molecule; Mycoplasma; colorimetry; conformation; gel electrophoresis; infrared spectrometry; lipid structure; membrane lipids; membrane model; membrane proteins; phase change; phospholipids; protein structure function; pulmonary surfactants; respiratory protein; thermodynamics; ultracentrifugation

The long-term objective of this laboratory is to determine how the structures of lipids and proteins are altered upon their mutual interaction in a hierarchy of model membrane systems of increasing complexity, and how these structural modifications are related to function. The developed protocols can be transferred to more complex and/or technically difficult but physiologically more relevant experimental paradigms such as monolayers in situ at the A/W interface. General principles extracted from specific examples strengthen the basis for understanding the organization of biological interfaces and how these are altered during pathological states. The specific aim for the MBRS project has a physical and a biological/biomedical component, which will be pursued during the next funding period; The physical aim is to develop FT-IR technology for the direct molecular characterization of conformational and orientational order of both lipids and proteins in situ in monolayers at the A/W interface. We have constructed a novel external reflection (IRRAS) apparatus that has permitted us to acquire the first IR spectra of protein monolayer films at the A/W interface, and thus obtain secondary structure and orientation information. We will continue to develop and improve both the apparatus and the optical spectroscopic models for quantitative interpretations of results. The biomedical application of this technology will be to evaluate structure/function relationships in a physiologically essential yet biochemically manageable system, lung surfactant. IRRAS provides a unique means to test the major hypothesis formulated to describe the molecular mechanism of surfactant function, the "squeeze-out" hypothesis. This hypothesis requires that the major phospholipid component of the surfactant (DPPC) becomes enriched at the major phospholipid component of the surfactant (DPPC) becomes enriched at the surface during successive expansion-compression cycles in vitro (exhalation-inhalation cycles in vivo), to produce the requisite low surface tension at the air-water interface (air-alveolar interface in vivo). We will address several aspects of the hypothesis, including its occurrence, its dependence on lipid structure and conformation, the roles of the surfactant proteins SP-B and SP-C, the effects of compression rates, modification of the subphase, etc. as they alter squeeze-out parameters.

该实验室的长期目标是确定如何 脂质和蛋白质的结构因相互作用而改变 在复杂性不断增加的模型膜系统层次结构中，以及如何 这些结构修饰与功能相关。 所开发的 协议可以转移到更复杂和/或技术上困难的 但生理上更相关的实验范例，例如单层细胞 在 A/W 接口处原位。 从具体内容中提取的一般原则 例子加强了理解组织的基础 生物界面以及这些界面在病理状态下如何改变。 MBRS 项目的具体目标有一个物理目标和一个目标： 生物/生物医学部分，这将在下一个阶段进行 资助期限； 物理目标是开发用于直接分子分析的 FT-IR 技术 两种脂质的构象和取向顺序的表征 以及 A/W 界面单层中的原位蛋白质。 我们有 构建了一种新颖的外部反射（IRRAS）装置 使我们能够获得第一个蛋白质单层膜的红外光谱 A/W界面，从而获得二级结构和取向 信息。 我们将继续开发和改进这两种设备 以及用于定量解释的光学光谱模型 结果。 该技术的生物医学应用将是评估 生理学上必需的结构/功能关系 生化管理系统，肺表面活性物质。 IRRAS 提供了独特的 是指测试用来描述分子的主要假设 表面活性剂功能的机制，“挤出”假说。 这 假设要求表面活性剂的主要磷脂成分 (DPPC) 在主要磷脂成分中富集 表面活性剂（DPPC）在连续的过程中在表面富集 体外膨胀-压缩循环（呼气-吸气循环） vivo），在空气-水之间产生必要的低表面张力 界面（体内空气-肺泡界面）。 我们将解决几个 假设的各个方面，包括它的发生、它的依赖 脂质结构和构象，表面活性蛋白 SP-B 的作用 和 SP-C，压缩率的影响，子相的修改， 等等，因为它们改变了挤出参数。