MECHANOCHEMISTRY OF MEMBRANES AND OTHER CELL COMPONENTS

膜和其他细胞成分的机械化学

• 批准号: 3342704
• 负责人: Richard E Waugh
• 金额: $ 13.03万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-01-01 至 1997-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3342704
• 关键词: acidity /alkalinity; actins; ankyrins; band 3 protein; chemical association; congenital blood disorder; congenital hemolytic anemia; cytoskeletal proteins; erythrocyte membrane; gel electrophoresis; glycophorin; hereditary elliptocytosis; hereditary spherocytosis; human subject; immunofluorescence technique; ionic strengths; lipid bilayer membrane; mechanical pressure; mechanical stress; membrane activity; membrane lipids; membrane proteins; membrane structure; molecular pathology; oxidation reduction reaction; protein structure function; sickle cell anemia; spectrin; thalassemia

The aim of this proposal is to understand how the mechanical properties of blood cells change when there are abnormalities or alterations in their structural components. In this particular proposal, the research focuses on the stability of the red blood cell membrane and the associations among the structural proteins of the membrane that give it its stability. Bilayer membranes by themselves are inherently unstable mechanically because they lack an elastic resistance to elongational deformation. Therefore, the presence of the membrane skeleton and its proper association with the bilayer are essential for cell survival. Abnormalities in membrane structural proteins or their interactions with one another are known to result in hemolytic anemia. In addition to developing more precise descriptions of the mechanical properties of the membrane skeleton in situ, the proposed research focuses primarily on the interaction between the membrane skeleton and the bilayer. Newly developed physical methods will be used to measure the strength of the bilayer skeletal interaction in normal cells and in cells with structural abnormalities or alterations. In addition, ultrastructural studies using antibodies or fluorescent labels that recognize specific membrane proteins will be used to determine the molecular events that are associated with the mechanical separation of bilayer and skeleton and to determine how these events are affected by structural changes in the intact membrane. The physical methods involve the formation of thin, cylindrical bilayer strands (tethers) from the cell surface in single cell micromechanical experiments. The forces applied to the cell and the corresponding changes in the cellular geometry are measured and interpreted quantitatively in terms of the energy of association between the bilayer and the skeleton. The structural alterations to be examined include: a) naturally occurring abnormalities in the membranes of patients with different forms of hemolytic anemia including hereditary spherocytosis, hereditary elliptocytosis, sickle cell disease and thalassemia; b) alterations in the structure of normal membranes as a result of chemical manipulations including low ionic strength, high pH and oxidation; and c) structural alterations induced by. incorporation of skeletal proteins or protein fragments to compete with specific native associations within the membrane skeleton and between the skeleton and the bilayer. It is our expectation that a more detailed and precise understanding of the effects that structural alterations have on the mechanical function (stability) of the membrane will result in a better understanding of the pathophysiology of hemolytic anemia and could ultimately lead to improved strategies for treating patients with hemolytic disease.

该提议的目的是了解机械性能如何 当存在异常或改变时，血细胞会改变 它们的结构成分。 在这个特定的提议中，研究 着重于红细胞膜的稳定性和 膜的结构蛋白之间的关联 它的稳定性。 双层膜本质上是不稳定的 机械上是因为它们缺乏对伸长率的弹性抗性 形变。 因此，膜骨骼的存在及其 与双层的正确关联对于细胞存活至关重要。 膜结构蛋白异常或其与其与其相互作用 已知彼此会导致溶血性贫血。 此外 制定更精确的描述的机械性能 膜骨架原位，拟议的研究主要关注 膜骨骼与双层之间的相互作用。 新 开发的物理方法将用于衡量 正常细胞和具有结构的细胞中的双层骨骼相互作用 异常或改变。 此外，使用 识别特定膜的抗体或荧光标签 蛋白质将用于确定分子事件 与双层和骨骼的机械分离以及到 确定这些事件如何受到结构变化的影响 完整的膜。 物理方法涉及薄的形成 单个细胞表面的圆柱双层链（Tethers） 细胞微力机械实验。 应用于细胞的力和 测量细胞几何形状的相应变化，并 用数量解释 双层和骨骼。 要检查的结构变化 包括：a）在膜上天然异常 具有不同形式的溶血性贫血的患者包括遗传 球细胞增多症，遗传性椭圆细胞增多症，镰状细胞疾病和 地中海贫血； b）正常膜的结构改变为A 化学操作的结果，包括低离子强度，高pH值 和氧化； c）由结构改变。合并 骨骼蛋白或蛋白质片段与特定本地竞争 膜骨骼内以及骨骼之间的关联 双层。 我们期望更详细和精确 了解结构改变对 膜的机械功能（稳定性）将导致更好 了解溶血性贫血的病理生理学，可以 最终导致改善治疗患者的策略 溶血疾病。