LIPID CONTROL OF MEMBRANE PROTEIN ORGANIZATION

膜蛋白组织的脂质控制

• 批准号: 2331953
• 负责人: RICHARD MENDELSOHN
• 金额: $ 21.58万
• 依托单位: RUTGERS THE STATE UNIV OF NJ NEWARK
• 依托单位国家: 美国
• 财政年份: 1982
• 资助国家: 美国
• 起止时间: 1982-02-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2331953
• 关键词: Mycoplasma; acyl group; biomedical equipment development; biophysics; conformation; fluorescence microscopy; infrared spectrometry; interferometry; intermolecular interaction; lipid bilayer membrane; mathematical model; melittin; membrane lipids; membrane proteins; membrane structure; microorganism growth; molecular film; phosphatidylcholines; phospholipids; physical model; pulmonary surfactants; reflection spectrometry; saturated /unsaturated bonds; structural biology; surface property

The long-term objective of this work is to determine how lipid and protein structures are altered upon their mutual interaction in a hierarchy of model membrane systems of increasing complexity, and how these alterations are related to function. Novel FT-IR experiments yield quantitative information about membrane lipid conformations in phospholipid vesicles or monolayer films. The developed protocols are applicable to more technically difficult but physiologically relevant experimental paradigms such as living cells. Two specific aims, each with physical and biological components, are planned: (AIM 1, PHYS.): To determine the number of 1-, 2-, and 3-bond acyl chain conformational states in structurally disordered, biologically relevant phases such as the Lalpha or the H/II. (AIM 1, BIO.): To detect quantitative IR conformational marker bands in the live cell membranes of a microorganism (A. laidlawii B). Chain conformations in intact cells will be studied under a variety of conditions of interest including its response to altered growth phases and temperatures, and addition of functionally disruptive agents. (AIM 2, PHYS.): To develop FT-IR for the molecular characterization of conformational and orientational order of both lipids and proteins in situ in monolayers at the A/W interface. We have built a novel external reflection (IRRAS) apparatus that has permitted acquisition of the first protein monolayer IR spectra. (AIM 2, BIO.): To evaluate structure/function relationships in the physiologically essential lung surfactant system. IRRAS provides a unique test of the "squeeze-out" hypothesis of pulmonary surfactant function. This hypothesis requires that the major lipid component of surfactant becomes enriched at the A/W interface during successive expansion-compression cycles (exhalation- inhalation cycles in vivo) to produce the requisite low surface tension. We will examine the occurrence of squeeze-out, its dependence on lipid structure and conformation, and the ability of surfactant proteins, to alter squeeze-out parameters. These experiments will permit rational design of therapeutic agents for infant respiratory distress syndrome (RDS) and its adult counterpart (ARDS).

这项工作的长期目标是确定脂质和蛋白质 结构在它们的相互作用下改变， 模拟日益复杂的膜系统，以及这些变化是如何发生的， 与功能有关。 新颖的FT-IR实验产生定量的 关于磷脂囊泡中膜脂质构象的信息， 单层膜 开发的协议适用于更多 技术上困难但与生理学相关的实验范例 例如活细胞。 两个具体的目标，每一个都有物理和 计划的生物组件：（AIM 1，PHYS）： 确定 1-，2-和3-键酰基链构象状态的数量， 结构上无序的，生物学上相关的阶段，如Lalpha 或H/II。 (AIM 1，BIO.）： 检测定量IR构象 微生物活细胞膜中的标记带（A.氏无 B）。 完整细胞中的链构象将在各种条件下进行研究。 包括其对改变的生长阶段的反应 和温度，以及添加功能破坏剂。 (AIM二、 PHYS）： 建立了FT-IR光谱技术， 脂质和蛋白质在原位的构象和取向顺序 在A/W界面的单层中。 我们建立了一个新颖的外部 反射（IRRAS）设备，其已经允许获取第一个 蛋白单层红外光谱。 (AIM 2，BIO.）： 评价 生理学上重要的肺的结构/功能关系 表面活性剂体系 IRRAS提供了一个独特的“挤出”测试 肺表面活性物质功能假说 这一假设要求 表面活性剂的主要脂质组分在A/W处富集， 在连续的膨胀-压缩循环（呼气- 体内吸入循环）以产生必需的低表面张力。 我们将研究挤出的发生，它对脂质的依赖性， 结构和构象，以及表面活性剂蛋白质的能力， 改变挤出参数。 这些实验将允许理性的 婴儿呼吸窘迫综合征治疗药物的设计 (RDS)其成人版（ARDS）。