Plasmodium heme detoxification probes

描述（由申请人提供）：高通量筛选（HTS）最近提供了数百种新的化合物，这些化合物已被证明能破坏血红素的形成，血红素是疟原虫色素的合成对应物，疟原虫色素是疟疾寄生虫中一种重要的血红素解毒产物，被认为是一种重要的药物靶标。原型疟原虫色素抑制剂氯喹最近已显示引起疟疾寄生虫恶性疟原虫（Plasmodium falciparum）中游离血红素的显著增加，并通过吸附到疟原虫色素晶体表面上来破坏血红素形成。我们推测，疟原虫色素抑制发生通过吸附到晶面和寄生虫生长抑制是直接相关的寄生虫中存在的游离血红素。因此，HTS发现的多种新的血红素抑制支架的财富提供了一个独特的机会，以探索和理解结构，吸附，游离血红素水平和寄生虫生长抑制之间的关系。为此，提出了以下具体目标：具体目标1。研究HTS的命中是否抑制血红素解毒途径。具体目标2.研究了高温冲击对高铁血红素的动力学影响及吸附行为.具体目标3.合成命中化合物的衍生物以探测Kads之间的结构-活性关系，增加细胞中的游离血红素和寄生虫IC 50。为了实现这些目标，这项研究将作为开普敦大学（UCT）的蒂莫西·J·埃根和凯瑟琳·A·埃森之间的合作项目进行。de Villiers-Chen和大卫W.赖特在范德比尔特大学（VU），纳什维尔，田纳西州。开发游离血红素测定和合成新化合物以探测这些关系将在UCT中进行。不同支架对寄生虫中游离血红素水平的影响的筛选将主要在VU进行，而动力学和分子对接研究将在SU进行。这三个小组之间的合作将具有很强的协同作用，并建立在所有三个小组之间现有的密切联系和积极合作的基础上。在寄生虫游离血红素和动力学测量的相当大的专业知识将从UCT和SU转移到VU。相反，筛选技术的专业知识将从VU转移到UCT和SU，扩大现有的专业知识转移。

DESCRIPTION (provided by applicant): High throughput screening (HTS) has recently provided hundreds of new compounds that have been shown to disrupt formation ß-hematin, the synthetic counterpart of hemozoin, a crucial heme detoxification product in the malaria parasite believed to be an important drug target. The prototype hemozoin inhibitor, chloroquine, has recently been shown to cause a significant increase in free heme in the malaria parasite Plasmodium falciparum and to disrupt ß-hematin formation via adsorption onto the hemozoin crystal surface. We hypothesize that hemozoin inhibition occurs through adsorption onto the crystal face and that parasite growth inhibition is directly related to free heme present in the parasite. The wealth of diverse new ß-hematin inhibiting scaffolds found by HTS thus provides a unique opportunity to probe and understand the relationships between structure, adsorption, free heme levels and parasite growth inhibition. To achieve this, the following specific aims are proposed: SPECIFIC AIM 1. Investigate whether hits from HTS inhibit the heme detoxification pathway. SPECIFIC AIM 2. Study the kinetic effects and adsorption behavior of HTS hits on ß-hematin. SPECIFIC AIM 3. Synthesize derivatives of hit compounds to probe structure-activity relationships between Kads, increased free heme in the cell and parasite IC50. In order to achieve these goals, the research will be conducted as a collaborative project between Timothy J. Egan at the University of Cape Town (UCT), Katherine A. de Villiers-Chen at Stellenbosch University (SU), South Africa and David W. Wright at Vanderbilt University (VU), Nashville, TN. Development of the free heme assay and synthesis of new compounds to probe these relationships will be conducted UCT. Screening of the effects of diverse scaffolds on free heme levels in the parasite will be performed largely at VU, while kinetic and molecular docking studies will be performed at SU. The collaboration between the three groups will be strongly synergistic and builds on existing strong links and active collaboration between all three. The considerable expertise in measurement of parasite free heme and kinetics will be transferred from UCT and SU to VU. Conversely, expertise on screening technology will be transferred from VU to UCT and SU, extending existing expertise transfer.