PLASMODIUM FALCIPARUM ASPARTIC PROTEINASE INHIBITOR DEVELOPMENT

提出的研究项目的目标是在分子水平上理解 水平，并抑制天冬氨酸血红蛋白酶的功能 启动人类疟疾寄生虫疟原虫中的血红蛋白降解 恶性疟原虫。这种微生物导致数亿人患病。 每年有数以百万计的儿童死亡，这是人们关注的问题 仅在这个国家，每年就有100万游客。寄生虫不断生长 通过分解宿主红细胞血红蛋白并使用产生的氨基 酸是主要的营养来源。我们已经证明了体内的起始酶 分解代谢途径是一种天冬氨酸蛋白酶，它只进行一次裂解。 解开血红蛋白分子，让它更有效地暴露出来 蛋白质分解。我们已经发现了一种选择性的肽类抑制剂 阻断血红蛋白酶作用，杀死培养中的恶性疟原虫。 这种蛋白酶似乎是一个有效的药物靶点。我们现在建议研究一下 更详细地介绍了该酶的性质及其与 抑制剂，利用重组酶过表达的工具，分子 建模、结晶学和定点突变。我们的目标是 更好地了解这种重要酶的结构和功能，如 以及提高抑制蛋白水解酶的效力和选择性。这个 其他项目组在蛋白质表达、分子方面的专业知识 相互作用和超微结构本地化将是 这一努力。预计拟议的实验将导致 一种严重的预防和治疗候选药物的开发 疟疾的治疗。

The goal of the proposed research project is to understand at a molecular level and to inhibit the function of the aspartic hemoglobinase that initiates hemoglobin degradation in the human malaria parasite, Plasmodium falciparum. This organism causes disease in several hundred million people, death in millions of children each year, and is of concern to over one million travelers per year in this country alone. The parasite grows by catabolizing host erythrocyte hemoglobin and using the resulting amino acids as major nutrient source. We have shown that the initial enzyme in the catabolic pathway is an aspartic protease that makes a single cleavage to unravel the hemoglobin molecule, exposing it for further, efficient proteolysis. We have found a selective peptidomimetic inhibitor that blocks hemoglobinase action and kills P. falciparum parasites in culture. This protease appears to be a valid drug target. We now propose to examine in greater detail the properties of the enzyme and its interaction with inhibitors, using the tools of recombinant enzyme overexpression, molecular modeling, crystallography, and site-directed mutagenesis. Our goal is to better understand the structure and function of this important enzyme, as well as to improve the potency and selectivity of protease inhibition. The expertise of the other project groups in protein expression, molecular interactions and ultrastructural localization will be an enormous asset to this endeavor. It is expected that the proposed experiments will lead to the development of a serious drug candidate for the prophylaxis and treatment of malaria.