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化合物，这些化合物已被证明可以破坏形成ß-血红素，这是血红素的合成对应物，是疟原虫中重要的血红素解毒产物，被认为是重要的药物靶点。原型血色素抑制剂氯喹最近已被证明可引起疟原虫恶性疟原虫中游离血红素的显著增加，并通过在血色素晶体表面的吸附破坏ß-血红素的形成。我们假设血红素抑制是通过吸附在晶面上发生的，寄生虫生长抑制与寄生虫中存在的游离血红素直接相关。因此，HTS发现的丰富多样的新型ß-血红素抑制支架为探索和理解结构、吸附、游离血红素水平和寄生虫生长抑制之间的关系提供了独特的机会。为实现这一目标，提出了以下具体目标：探讨HTS击中是否抑制血红素解毒途径。具体目标2。研究HTS命中对ß-血红素的动力学效应和吸附行为。具体目标3。合成hit化合物的衍生物，探索Kads、细胞中增加的游离血红素和寄生虫IC50之间的构效关系。为了实现这些目标，这项研究将作为开普敦大学（UCT）的Timothy J. Egan，南非Stellenbosch大学（SU）的Katherine a . de Villiers-Chen和田纳西州纳什维尔范德比尔特大学（VU）的David W. Wright的合作项目进行。UCT将进行自由血红素测定和新化合物合成的开发，以探索这些关系。筛选不同支架对寄生虫中游离血红素水平的影响将主要在VU进行，而动力学和分子对接研究将在SU进行。三个小组之间的合作将在三者之间现有的牢固联系和积极合作的基础上进行强协同。在寄生虫游离血红素测量和动力学方面的大量专业知识将从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.