Development of Eppin as a Male Contraceptive

描述（由申请人提供）：本研究项目的长期目标是开发eppin作为男性避孕目标。我们一直在研究eppin与人精子表面的精球蛋白的相互作用，特别是关于射精后精子活力的恢复。自2004年我们在《科学》杂志上发表了一篇关于免疫高滴度eppin的雄性猴子完全可逆避孕的文章以来，我们一直在研究eppin作为一种可药物靶点。本申请提出了开发一种抑制肾上腺素半胶质结合的可药物化合物的详细步骤。当eppin - semenogelin结合被阻断时，精子活力被有效抑制。该项目将与NCCU BRITE中心的药物发现研究计划联合（分包）。具体目标#1是通过定向文库筛选（hit generation）鉴定新的、有效的和高度特异性的epin -semenogelin结合抑制剂。基于我们在化合物A4上的初步数据，本目的将验证一种假设，即可以鉴定出更有效和特异性的epin -semenogelin结合抑制剂化合物。为了确定这一特定目标的抑制剂，将建立3个开发单元来协调BRITE中心的研究流程：(1)分析开发单元，(2)分析实施单元，(3)筛选和HTS单元。特异性目标#2是通过药物化学和分子模型（hit-to-lead优化）对特异性目标#1中确定的初始靶点进行迭代改进，以提高效力、选择性和细胞通透性，并降低细胞毒性。具体目标#2将建立两个工作单元：(1)化学单元和(2)化学信息学单元。特异性目标#3将更好地定义在特异性目标#1和#2中发现的semenogelin和化合物的eppin上的靶点。利用epin -semenogelin体外实验，重组epin蛋白片段和具有突变关键氨基酸残基的epin将被用来更好地确定epin上的semenogelin（或化合物，例如A4）结合位点。这个特定的目标将测试这样一个假设，即准确地定义哪些外排素氨基酸对semenogelin和/或靶化合物结合是必需的，将使我们能够改进化合物的特异性。

DESCRIPTION (provided by applicant): The long-term goals of this research project are to develop eppin as a male contraceptive target. We have been studying the interaction of eppin with semenogelin on the human sperm surface, particularly with regard to the resumption of sperm motility following ejaculation. Since our publication in Science in 2004 on the complete and reversible contraception of male monkeys immunized to a high titer with eppin, we have been investigating eppin as a drugable target. This application presents the detailed steps necessary for developing a drugable compound that inhibits eppin semenogelin binding. When eppin semenogelin binding is blocked, sperm motility is effectively inhibited. This project will be in conjunction (subcontract) with the drug discovery research program at the BRITE center, NCCU. Specific aim #1 is the identification of novel, potent and highly specific inhibitors of eppin-semenogelin binding through directed library screening (hit generation). Based on our preliminary data on compound A4, this aim will test the hypothesis that more potent and specific inhibitor compounds of eppin-semenogelin binding can be identified. To identify inhibitors in this specific aim, 3 development units will be established to coordinate the research flow at the BRITE Center: (1) Assay Development Unit, (2) Assay Implementation Unit (3) Screening and HTS Unit. Specific aim #2 is the iterative improvement of initial hits identified in Specific Aim #1 with medicinal chemistry and molecular modeling (hit-to-lead optimization) to improve the potency, selectivity and cell permeability and to decrease the cell toxicity. Specific aim #2 will establish 2 working units: (1) The Chemistry Unit and (2) The Cheminformatics Unit. Specific aim #3 will better define the target site on eppin for semenogelin and compounds discovered in specific aims #1 and #2. Using the eppin-semenogelin in vitro assays, recombinant eppin protein fragments and eppin with mutated key amino acid residues will be used to better define the semenogelin (or compound, e.g., A4) binding site on eppin. This specific aim will test the hypothesis that defining exactly which eppin amino acids are essential for semenogelin and/or a target compound binding will enable us to refine the specificity of the compound. PUBLIC RELEVANCE: This research project seeks to develop a new non-steroidal male contraceptive that will allow males greater choices than condoms or vasectomy. Wide spread availability of male contraceptives will enhance family planning throughout the world.