Rational Development of Anti-Trypanosoma Cruzi Drugs

描述（由申请人提供）：本研究项目的总体目标是发现可开发成治疗恰加斯病的药物的先导化合物。这种威胁生命的疾病是由感染原生动物病原体克氏锥虫（克氏锥虫）引起的。它在南美洲和中美洲流行，每年有1.16亿人受到慢性感染，约14 000人死亡。据信有超过10万美国公民被感染。目前的治疗方案不足以治愈这种感染，因此需要研究发现更好的化疗方法。该项目将专注于制造克氏锥虫甾醇14-去甲基酶（Tc14DM）的抑制剂，该酶是克氏锥虫甾醇生物合成的关键酶。该酶是唑类抗真菌药物的靶点，是一种公认的抗菌靶点。我们假设可以用最优的抗t合成新的化合物。这些将足够活跃，以治疗动物（和人类）慢性克氏锥虫感染。我们提供了两种结合Tc14DM的新化学类的初步数据，这些化学类对克氏锥虫培养物具有有效的活性。具体目的是：1)合成替法尼类似物作为潜在的克氏t淋巴细胞化疗药物。替法尼是一种含咪唑的化合物，正在开发用于癌症治疗，具有良好的药代动力学性质。2)合成一系列双取代咪唑作为潜在的克氏弓形虫化疗药物。初步数据表明，该系列具有较强的抗t。感染小鼠口服克氏菌活性。3)对Tc14DM进行分子建模和结构测定。基于原核CYP51结构的分子模型将最初用于指导基于结构的药物设计。同时，酶与结合抑制剂的晶体结构将被追求，以帮助指导药物设计。4)建立Tc14DM的竞争结合试验。提出的荧光偏振分析将有助于中高通量筛选化合物。5)测试化合物的功效、药代动力学和毒性。将采用一系列体外筛选，然后在小鼠模型中测试选定的化合物。

DESCRIPTION (provided by applicant): The overall goal of this research project is to discover lead compounds that can be developed into therapeutics for treatment of Chagas disease. This life-threatening disease results from infection with the protozoan pathogen Trypanosoma cruzi (T. cruzi). It is endemic in South and Central America, with >16 million people chronically infected and approximately 14,000 deaths per year. More than 100,000 USA citizens are believed to be infected. Current treatment options are inadequate to cure this infection, thus research is needed to discover better chemotherapeutics. The project will focus on making inhibitors to a key enzyme involved in sterol biosynthesis in T. cruzi, sterol 14-demethylase (Tc14DM). This enzyme, the target of azole antifungal drugs, is a well established antimicrobial target. We hypothesize that new compounds can be synthesized with optimal anti-T. cruzi activity and these will be sufficiently active to cure animals (and humans) with chronic T. cruzi infection. We provide preliminary data on two new chemical classes that bind the Tc14DM and that have potent activity against T. cruzi cultures. The specific aims are: 1) Synthesize analogs of tipifarnib as potential T. cruzi chemotherapeutics. Tipifarnib is an imidazole- containing compound under development for cancer therapy and has excellent pharmacokinetic properties. 2) Synthesize a series of disubstituted imidazoles as potential T. cruzi chemotherapeutics. Preliminary data shows that this series has potent anti-T. cruzi activity when given orally to infected mice. 3) Perform molecular modeling and structure determination of Tc14DM. A molecular model based on a prokaryotic CYP51 structure will initially be utilized to guide structure-based drug design. Concomitantly, a crystal structure of the enzyme with bound inhibitors will be pursued to help guide drug design. 4) Develop a competition binding assay for Tc14DM. The proposed fluorescence polarization assay will assist moderate- to high-throughput screening of compounds. 5) Test compounds for efficacy, pharmacokinetics, and toxicity. A series of in vitro screens will be employed followed by testing selected compounds in mouse models.