ERYTHROCYTE MEMBRANE STRUCTURE

由于红细胞膜被认为是许多动物细胞的模型 由于该模型被用于设计质膜 与许多组织和疾病有关的实验，重要的是 模型是正确的。这项建议的目的是完善/更正 模型的某些方面目前可能不准确，特别是 与膜的结构和功能有关的那些方面 最丰富的蛋白质，带3。第一，细胞质的结构 带3(Cdb3)的结构域将通过x射线结晶学确定，以及 其重要功能构象的分子基础 平衡将通过定点突变进行评估。由于cdb3 为锚蛋白，蛋白4.1，蛋白4.2， 血红蛋白、半红细胞和几种糖酵解酶的拆分 S的三维结构应该允许膜的精细化 其主要组织中心之一的体系结构。二、角色定位 带3-锚蛋白-血影蛋白桥在决定膜形状和 将对机械性能进行评估。因为令人信服的性质 过去的研究记录了基于血影蛋白的膜的重要性 骨架在控制细胞形态/变形性方面很少受到关注 针对膜-骨骼的可能贡献 锚定在膜性能调节中的作用。因此，可以使用 具体地说，切断锚链到细胞膜的系绳将被用来 检视蛋白质桥在维持细胞膜中的重要性 形态/稳定性。最后，分析了波段3聚类之间的关系 并将在活体内定量测量红细胞清除率， 自然产生的促进这一过程的ti-Band 3免疫球蛋白的表位 通行证将会确定。综上所述，拟议的研究应 扩大我们对蛋白质分子组织的理解 包括一个健康的红细胞膜，并有助于澄清 促进将不健康/衰老的细胞迅速从循环中移除。

Since the red cell membrane is considered a model of many animal cell plasma membranes and because this model is used in the design of experiments relating to many tissues and diseases, it is important that the model be correct. The purpose of this proposal is to refine/correct certain aspects of the model that may be currently inaccurate, especially those aspects pertaining to the structure and function of the membrane's most abundant protein, band 3. First, the structure of the cytoplasmic domain of band 3 (cdb3) will be determined by x-ray crystallography, and the molecular basis of its functionally important conformational equilibrium will be evaluated by site-directed mutagenesis. Since cdb3 provides a membrane binding site for ankyrin, protein 4.1, protein 4.2, hemoglobin, hemichromes and several glycolytic enzymes, resolution of cdb3's 3-dimensional structure should allow refinement of the membrane's architecture at one of its major centers of organization. Second, the role of the band 3-ankyrin-spectrin bridge in determining membrane shape and mechanical properties will be evaluated. Because of the compelling nature of past research documenting the importance of the spectrin-based membrane skeleton in control of cell morphology/deformability, little attention has been directed towards the possible contribution of membrane-skeletal anchors in regulation of membrane properties. Therefore, methods that specifically sever the ankyrin tether to the membrane will be exploited to examine the importance of the protein bridge in maintaining membrane morphology/stability. Finally, the relationship between band 3 clustering and erythrocyte clearance will be quantitively measured in vivo, and the epitope of the naturally occurring a ti-band 3 IgG that promotes this clearance will be identified. Taken together, the proposed studies should expand our understanding of the molecular organization of the proteins that comprise a healthy erythrocyte membrane, and help clarify the changes that promote the rapid removal of an unhealthy/senescent cell from circulation.