NADH-FUMARATE REDUCTASE--A TARGET AGAINST CHAGAS DISEASE

克氏锥虫是查格斯氏病的病原体，持续时间长， 使人丧失行为能力，通常是致命的疾病。大约有1800万人 在中美洲和南美洲都感染了这种寄生虫。虽然 在美国本土感染非常罕见，有几个病例 因输血或器官而发生的报道 移植。此外，最近的研究指出，2%(洛杉矶) 洛杉矶)至5%(华盛顿特区)居住在美国的拉美裔美国人 被感染了。不仅这些人可能促成了疾病的传播， 但它们也可能会出现并发症，从而导致 医疗费用的增加。目前，还没有药物可以用来 治疗这种疾病的慢性形式，即使有几个目标 靶标是All中存在的NADH-富马酸还原酶 克氏锥虫生命周期中的各个阶段，但在哺乳动物中不存在 细胞。在过去的几年里，我们研究了这种酶的作用。 利用布氏毛滴虫原环类鞭毛虫作为非感染性模型。 我们已经提纯了这种酶，研究了它的亚细胞定位和 发现了强大的抑制剂，不仅能在体外阻断这种酶 还能抑制布氏毛滴虫原环类鞭毛虫在培养中的生长。 这些抑制剂中有几种可以阻断富马酸NADH还原酶。 克氏锥虫T.ruzi epimasches.我们建议评估这种酶是否 构成了开发有效化疗的合适靶点 对抗恰加斯病。本项目的具体目标包括：1) 克氏锥虫NADH-富马酸还原酶的纯化 附生体用来测试抑制剂并确定它们的效力；2) 富马酸还原酶抑制剂(四种)的疗效评价 我们实验室合成的和两个商业上的)。 表鞭毛体、类鞭毛体和无鞭毛体(在哺乳动物中生长 细胞)；3)细胞内浓度变化的测定 代谢中间产物(即琥珀酸、富马酸、三磷酸腺苷和二氢化二磷酸) 由富马酸还原酶抑制剂引起。这些实验将提供 关于NADH-富马酸还原酶作为一种 针对恰加斯病的目标。

Trypanosoma cruzi is the causal agent of Chagas' disease, a long lasting, incapacitating and often lethal disease. Approximately 18 million people in Central and South America are infected with this parasite. Although the autochthonous infection in the US is very rare, several cases have been reported occurring as a consequence of blood transfusion or organ transplantation. More over, recent studies have pointed out that 2% (Los Angeles) to 5% (Washington, DC) of the hispanics living in the US are infected. Not only these people may contribute to spreading the disease, but also they are likely to suffer complications therefore contributing to increases in health cost. Currently, there are no drugs available to treat the chronic form of this disease, even though several target targets is the enzyme NADH-fumarate reductase which is present in all stages during the life cycle of T. cruzi but is not present in mammalian cells. In the last few years we have investigated the role of this enzyme utilizing T. brucei procyclic trypomastigotes as a non infective model. We have purified the enzyme, studied its subcellular localization and identified powerful inhibitors that not only block the enzyme in vitro but also inhibit T. brucei procyclic trypomastigotes growth in culture. Several of these inhibitors block the enzyme NADH-fumarate reductase of T. cruzi epimastigotes. We propose to evaluate whether this enzyme constitutes a suitable target to develop an effective chemotherapy against Chagas' disease. The specific aims of this project include: 1) Purification of the enzyme NADH-fumarate reductase from T. cruzi epimastigotes to test inhibitors and determine their potency; 2) evaluation of efficacy of fumarate reductase inhibitors (four of them synthesized in our laboratory and two commercially available) on T. cruzi epimastigotes, trypomastigotes and amastigotes (grown in mammalian cells); 3) Determination of changes in the intracellular concentration of metabolic intermediates (i.e., succinate, fumarate, ATP and NADH) caused by fumarate reductase inhibitors. These experiments will provide important information regarding the enzyme NADH-fumarate reductase as a target against Chagas' disease.