Optimization of biliverdin IXβ reductase redox inhibitors as novel reagents for enhancing platelet production

项目主任/首席调查员(最后、第一、中间)：Nesbitt，Natasha M. 项目摘要/摘要 该第二阶段SBIR提案将支持我们正在进行的药物发现计划，该计划旨在开发和验证 调节人类血小板生成的新型药物靶点的小分子抑制剂。工作范围 建立在强有力的遗传和生化证据基础上的胆绿素IX的氧化还原依赖的酶活性 还原酶(BLVRB)在一个先前未知的巨核细胞发育和发育调控途径中的作用 增强了血小板的生成。在电子计算机虚拟筛选中，我们的新评分功能导致了对 预测有20种化合物可抑制BLVRB的氧化还原活性。生化和基于细胞的分析得到验证 这些化合物中有四个是该酶的有效抑制剂。一种互补的结晶学分析导致了 另外两个对BLVRB活性增强的化合物的鉴定。我们将聘请医药公司 和计算化学来优化我们的Hit化合物以开发具有更高效力的先导化合物 以及对BLVRB的选择性。这些化合物将通过体外造血试验进行进一步的表征。 并跟踪体内动物研究，显示与我们目前的Hit化合物相比，疗效有所改善。 这个项目的长期成功是基于计算化学、血小板等领域的协同专业知识 生物化学、结晶学和药物发现。成功完成这项拨款建议的研究 对一类新的血小板增强化合物的商业化开发具有重要意义 其功能独立于已知的促血小板生成素(TPO)/c-MPL受体轴。复合开发和 靶点验证提供了一种高度创新的策略，理论上可以绕过与 目前临床上使用的直接TPO/c-MPL激动剂(如血小板活化、血栓栓塞症、 和骨髓纤维化)，同时产生一流的氧化还原抑制剂，用于进一步的临床前开发。 PHS 398/2590(06/09版)页面 续订格式页面

Program Director/Principal Investigator (Last, First, Middle): NESBITT, Natasha M.. PROJECT SUMMARY/ABSTRACT This Phase II SBIR proposal will support our ongoing drug discovery program designed to develop and validate small molecule inhibitors of a novel drug target regulating platelet production in humans. The scope of work builds on strong genetic and biochemical evidence linking redox-dependent enzymatic activity of biliverdin IX reductase (BLVRB) in a previously-uncharacterized regulatory pathway of megakaryocyte development and enhanced platelet production. In silico virtual screening with our novel scoring function led to the identification of ~20 compounds predicted to inhibit the redox activity of BLVRB. Biochemical and cell-based assays validated four of these compounds as potent inhibitors of the enzyme. A complementary crystallographic assay led to the identification of two additional compounds with increased potency towards BLVRB. We will employ medicinal and computational chemistry to optimize our hit compounds to develop lead compounds with improved potency and selectivity for BLVRB. These compounds will be further characterized using in vitro hematopoietic assays and follow up in vivo animal studies to show improved efficacy in comparison to our current hit compounds. Long-term success of this project is predicated on synergistic expertise in computational chemistry, platelet biochemistry, crystallography, and drug discovery. Successful completion of the research proposed in this grant has fundamental relevance to commercial development of a new class of platelet enhancing compounds functioning independently of the known thrombopoietin (TPO)/c-MPL receptor axis. Compound development and target validation provide a highly innovative strategy that would theoretically bypass toxicities associated with direct TPO/c-MPL agonists currently in clinical use (such as platelet activation, thromboembolic complications, and bone marrow fibrosis), while generating first-in-class redox inhibitors for further pre-clinical development. PHS 398/2590 (Rev. 06/09) Page Continuation Format Page