LIPID CONTROL OF MEMBRANE PROTEIN ORGANIZATION

该实验室的长期目标是确定 脂质和蛋白质的结构在它们相互作用时发生改变 在日益复杂的模型膜系统的层次结构中， 这些结构修饰与功能有关。 发达 协议可以被转移到更复杂和/或技术上困难的 但生理学上更相关的实验范例， 在A/W接口处原位。 一般原则摘自具体的 实例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和 生物/生物医学部分，将在下一届会议期间继续进行。 融资期限; 物理目的是发展FT-IR技术， 两种脂质的构象和取向顺序的表征 和A/W界面处的单层中的原位蛋白质。 我们有 构建了一种新型的外部反射（IRRAS）装置， 使我们能够获得蛋白质单层膜的第一个红外光谱， A/W界面，从而获得二级结构和取向 信息. 我们将继续发展和改进这两种仪器 和光谱模型的定量解释 结果 这项技术的生物医学应用将评估 结构/功能关系在生理学上是必要的， 生化管理系统肺表面活性物质 IRRAS提供了一个独特的 测试主要假设的手段，这些假设是为了描述 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）变得富集在主要磷脂成分的 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（体外呼气-吸气循环） 体内），以在空气-水界面处产生必需的低表面张力 界面（体内空气-肺泡界面）。 我们将讨论几个 假设的各个方面，包括它的发生，它对 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，亚相的修改， 等因为它们改变挤出参数。

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.