LIPID CONTROL OF MEMBRANE PROTEIN ORGANIZATION

这个实验室的长期目标是确定 脂类和蛋白质的结构在它们相互作用时会发生变化 在日益复杂的模型膜系统的层次结构中，以及如何 这些结构上的修改与功能有关。已开发的 协议可以转移到更复杂和/或技术困难的 但生理上更相关的实验范式，如单分子层 在A/W界面处原位。从具体情况中提取的一般原则 举例加强了理解组织结构的基础 生物界面以及在病理状态下这些界面是如何改变的。 MBR项目的具体目标包括实物和 生物/生物医学组成部分，将在下一届 资金期； 物理目标是开发用于直接分子的红外光谱技术 两种脂类的构象和取向有序性的表征 和A/W界面单层中的原位蛋白质。我们有 构造了一种新型的外部反射(IRRAS)设备，该设备具有 使我们获得了第一个蛋白质单层膜的红外光谱 A/W接口，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 和用于定量解释的光学光谱模型 结果。 这项技术在生物医学上的应用将评估 生理上仍不可缺少的结构/功能关系 生化可控系统，肺表面活性物质。IRRAS提供了独特的 检验用来描述分子的主要假说的方法 表面活性剂的作用机理，即“挤出”假说。这 假说要求表面活性物质的主要磷脂成分 (DPPC)在主要的磷脂成分上变得富含 表面活性剂(DPPC)在连续的过程中在表面上变得富集化 体外扩张-压缩循环(呼气-吸入循环 Vivo)，以在空气-水中产生必要的低表面张力 界面(活体内的空气-肺泡界面)。我们将讨论以下几个问题 假说的各个方面，包括它的出现，它对 表面活性蛋白SP-B的脂质结构和构象及其作用 和SP-C，压缩速率的影响，子阶段的修改， 等，因为它们改变了挤出参数。

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.