Biomolecular Recognition with Artificial Alpha Helices

描述(申请人提供)：细胞功能依赖于生物分子(蛋白质、RNA、DMA和碳水化合物)之间高度特异的相互作用。α-螺旋是蛋白质结构中普遍存在的元素，在许多这些相互作用中发挥着基础作用。可以预测地破坏这些相互作用的α-螺旋模拟将是分子生物学中的宝贵工具，也是药物开发的潜在线索。现有的螺旋稳定方法的一个局限性是它们牺牲侧链的官能度来产生交联键和成核螺旋构象。修饰侧链使它们不能用于分子识别，并阻止推测的螺旋的至少一个面。我们已经成功地创造了一种合成短而稳定的α螺旋的通用方法，允许严格保存螺旋表面。我们的策略包括用共价键取代目标α-螺旋中的一个主链氢键。交联剂的内部放置使其能够利用完整的螺旋功能进行分子识别。在初步研究中，我们已经证明了这种新方法可以产生异常稳定的人工α-螺旋。在这个应用中，我们探索了这些人工螺旋用于识别特定的蛋白质口袋和DNA主要凹槽的用途。 关于特定的目标，(1)我们将确定是否将假定的螺旋中的主链氢键替换为碳-碳键，从而不断产生高度稳定的螺旋多肽。(2)我们将制备针对模型(核糖核酸酶S和GCN4)和具有治疗意义的蛋白质-蛋白质相互作用(HIV-1gp41)的人工螺旋，以评估这些化合物的生物学效果。(3)我们将开始研究开发一类新的序列特异性DNA结合分子。将这三个目标结合起来，将验证一种新的人工α-螺旋制备方法及其在生物分子识别中的潜在应用。

DESCRIPTION (provided by applicant): Cellular function depends on highly specific interactions between biomolecules {proteins, RNA, DMA, and carbohydrates). Alpha-helices, ubiquitous elements of protein structures, play fundamental roles in many of these interactions. Alpha-helix mimetics that can predictably disrupt these interactions would be invaluable tools in molecular biology, and potential leads in drug development. A limitation of existing methods for helix stabilization is that they sacrifice side chain functionality to create crosslinks and nucleate helical conformations. Modifying side chains makes them unavailable for molecular recognition and blocks at least one face of the putative helix. We have succeeded in creating a general approach for the synthesis of short stable alpha helices that allows strict preservation of the helix surfaces. Our strategy involves replacement of one of the main chain hydrogen bonds in the target alpha-helix with a covalent bond. The internal placement of the crosslink makes it possible to take advantage of the full helix functionality for molecular recognition. In preliminary studies, we have demonstrated that this new method results in unusually stable artificial alpha-helices. In this application, we explore the utility of these artificial helices for recognition of specific protein pockets and DNA major grooves. With regards to specific aims, (1) we will determine whether replacement of a main chain hydrogen bond in a putative helix with a carbon-carbon bond continually results in highly stable and helical peptides. (2) We will prepare artificial helices that target model (RNase S and GCN4) and therapeutically important protein-protein interactions (HIV-1 gp41) to assess the biological efficacy of these compounds. (3) We will initiate research efforts to develop a new class of sequence-specific DNA binding molecules. Combined these three aims will validate a new approach for the preparation of artificial alpha-helices and their potential use in biomolecular recognition.