RED CELL MEMBRANE SKELETON AND MALARIA INFECTION

这项建议的长期目标是继续研究 红细胞膜相互作用的功能后果 蛋白质和蛋白质由红细胞内阶段精制而成 恶性疟原虫。发生了深刻的变化 感染后红细胞的特性，包括显著降低 可变形性和粘附性增加。假设我们会 探索的是，寄生虫介导的红细胞特性的变化是 不同寄生虫来源的蛋白相互作用的结果 特定的红细胞膜蛋白。为了实现这些目标，我们 提出以下四个具体目标：1)定义生物物理学 特定疟疾蛋白之间相互作用的后果 红细胞膜骨架。我们将确定这些措施的影响 蛋白质-蛋白质相互作用对膜伸长刚性的影响 粘度、膜机械完整性和横向迁移率 膜蛋白。待研究的寄生虫蛋白质包括 细胞黏附分子PfEMP-1和其他疟疾蛋白，包括 与红细胞特异结合的HRP-I、MESA、PfEMP-3和RESA 膜骨架；2)在分子水平上定义特定的 红细胞膜骨架蛋白与P. 获得恶性疟原虫蛋白质的详细了解如何特异性 受感染红细胞中的蛋白质-蛋白质相互作用可以诱导功能 细胞膜改变；3)确定各种疟疾的贡献 对蛋白质黏附强度的定量洞察 进入细胞黏附的过程。细胞黏附是一种主要的毒力 恶性疟原虫感染的致病因素及其相互作用 PfEMP-1蛋白与血管内皮细胞上的受体的关系。我们 将检查表达抗原变异体的寄生虫系 不同强度的PfEMP-1与同一配体结合，还 确定寄生虫制造的辅助蛋白，如台面， HRP-1和PfEMP-3调节黏附相互作用的强度；4) 研究特定红膜蛋白对疟疾的贡献- 通过比较寄生虫引起的红细胞功能的变化 正常红寄生虫感染后的生物物理后遗症 细胞与感染突变红细胞后所见的细胞 各种膜骨骼中的定性或定量缺陷 蛋白质。我们拥有的新颖的实验方法和独特的试剂 开发的数据将用于开展这些拟议的研究。这个 成功地实现了这些目标，使用分子工程在 与新的生物物理方法相结合，应该使我们能够 进一步加深对S作用机制的认识 重要的人类病原体。

The long-term objective of this proposal is to continue to examine the functional consequences of interaction between red cell membrane proteins and proteins elaborated by intraerythrocytic stages of the malarial parasite Plasmodium falciparum. Profound changes occur in the properties of red cell following infection, including markedly reduced deformability and increased adhesiveness. The hypothesis we will explore is that the Parasite-mediated changes in red cell properties are the result of different parasite derived proteins interacting with specific red cell membrane proteins. To accomplish these goals, we propose the following four specific aims: 1) Define the biophysical consequences of interaction between specific malarial proteins and the red cell membrane skeleton. We will determine the effects of these protein-protein interactions on membrane extensional rigidity, membrane viscosity, membrane mechanical integrity and lateral mobility of membrane proteins. The parasite proteins to be studies include the cytoadherence molecule PfEMP-1, and other malaria proteins including HRP-I, MESA, PfEMP-3, and RESA that bind specifically to the red cell membrane skeleton; 2) Define at the molecular level the specific interacting domains of red cell membrane skeletal proteins and P. Falciparum proteins to obtain detailed understanding of how specific protein-protein interactions in infected red cells can induce functional membrane alterations; 3) Define the contribution of various malarial proteins to the strength of adhesion of obtain quantitative insights into the process of cytoadherence. Cytoadherence is a major virulence factor in P. Falciparum infection and involves the specific interaction of the PfEMP-1 protein with receptors on vascular endothelial cells. We will examine whether parasite lines that express antigenic variants of PfEMP-1 bind with differing strengths to the same ligand and also determine whether accessory proteins made by the parasite, such as MESA, HRP-1 and PfEMP-3, modulate the strength of the adhesive interaction; 4) Examine the contributions of specific red membrane proteins to malarial- parasite induced changes in red cell function by comparing the biophysical sequelae that accompany parasite infection of normal red cells with those seen following infection of mutant red cells with either qualitative or quantitative defects in various membrane skeletal proteins. The novel experimental approaches and unique reagents we have developed will be used to carry out these proposed studies. The successful accomplishment of these aims, using molecular engineering in conjunction with novel biophysical approaches, should enable us to further our understanding to the mechanism(s) involved in action of an important human pathogen.