EPR STUDIES OF MEMBRANE PROTEINS

阴离子交换蛋白（带3）是一种100 k跨膜蛋白， 由两个不同区域组成的人红细胞膜 有两种不同的功能 完整的膜结构域 促进HCO 3-交换为Cl-，从而提供重要的 与远端组织CO2运输相关的生理功能 到肺部。 胞质结构域作为膜结合位点 对于外周蛋白质，包括那些参与桥接 细胞质结构域的膜骨架，从而提供了一个物理 连接膜骨架和双分子层。 后一种功能 对于保持双凹形状和独特的粘弹性是必不可少的 红细胞的特性。 正在进行的研究有长期的目标， 带3的结构特征对于其运输是重要的 第三带的动力学性质， 它与其他膜蛋白和膜脂质的相互作用。 这些研究将提供重要的见解， 带3在人红细胞和更广泛的红细胞中的机械特性 背景下，将进一步了解如何结构和动态 细胞膜的性质影响它们的功能性质。 在下一个授权期，电子顺磁共振，荧光， 和磷光光谱将被采用，结合 已开发的新分子探针，以解决以下问题 具体问题：1）膜脂的排序如何影响 运输功能带3？2)从人口的角度来看， 带3的旋转迁移率存在于红细胞中， 这些群体在多大程度上可以被分配到已知的蛋白质-蛋白质 互动？一个相关的问题是， 连接膜骨架的带3的胞质结构域， 脂质双分子层，以及在何种程度上这些链接存在于完整的 手机？3)特定蛋白质间相互作用的性质是什么 涉及条带3的胞质结构域和结合蛋白 部分纯化膜中的锚蛋白、蛋白4.1和蛋白4.2 系统？4）功能性建筑之间的空间布局是什么？ 带3上的重要阴离子结合位点和相邻带之间的界面 带3单体？在这些研究过程中，新的分子 探针，光谱方法和数据分析方法将是 开发这将是实用的生物医学研究界。

The anion exchange protein (band 3) is a 100 k transmembrane protein in the human erythrocyte membrane which is composed of two distinct domains that serve two distinct functions. The integral membrane domain facilitates the exchange of HCO3- for Cl-, thereby providing an important physiological function related to CO2 transport from the distal tissues to the lungs. The cytoplasmic domain serves as a membrane binding site for peripheral proteins including those involved in bridging the cytoplasmic domain to the membrane skeleton, thereby providing a physical link between the membrane skeleton and the bilayer. This latter function is essential for maintaining the biconcave shape and unique viscoelastic properties of the erythrocyte. Studies in progress have long-term goals of characterization of structural features of band 3 which are important for its transport function and elucidation of dynamic properties of band 3 which reflect its interactions with other membrane proteins and with membrane lipids. These studies will provide important insights into functional and mechanical properties of band 3 in human erythrocytes and in the broader context, will further understanding of how structural and dynamic properties of cell membranes affect their functional properties. In the next grant period, electron paramagnetic resonance, fluorescence, and phosphorescence spectroscopies will be employed, in conjunction with new molecular probes which have been developed, to address the following specific questions: 1) How does the ordering of membrane lipids affect the transport function band 3? 2) What populations, in terms of rotational mobility, of band 3 exist in the erythrocyte and to what extent can these populations be assigned to known protein-protein interactions? A related question is what are the mechanical properties of the cytoplasmic domain of band 3 which links the membrane skeleton to the lipid bilayer and to what extent do these links exist in the intact cell? 3) What are the properties of specific protein-protein interactions involving the cytoplasmic domain of band 3 and the binding proteins ankyrin, protein 4.1, and protein 4.2 in a partially purified membrane system? and 4) What is the spatial arrangement between the functionally important anion binding site on band 3 and the interface between adjacent band 3 monomers? During the course of these studies, new molecular probes, spectroscopic methods, and data analysis methods will be developed which will be of utility in the biomedical research community.