Novel antivirals targeting the RNase H activity of HIV reverse transcriptase

描述（由申请人提供）：高效抗逆转录病毒治疗（HAART）药物主要针对四种HIV酶中的三种：逆转录酶（RT）DNA聚合酶、蛋白酶和整合酶。尽管HAART在抑制HIV感染患者的病毒载量方面非常有效，但长期治疗不可避免地导致耐药病毒株的出现。因此，开发作用于新的HIV靶点的药物至关重要。第四种HIV酶，RT相关核糖核酸酶H（RNH）就是这样一种靶点. RNH在逆转录过程中降解病毒RNA基因组，对HIV复制至关重要。这是艾滋病毒唯一尚未被抗逆转录病毒药物解决的酶活性。这些药物可能对目前所有的耐药病毒株都有活性。我们的目标是开发在基于细胞的复制试验中具有纳摩尔功效的有效RNH抑制剂（RNHI），为此，我们将使用基于我们在结构生物学，计算生物学，药物化学，酶学，生物化学和病毒学方面的广泛专业知识的多学科方法。 我们将通过基于结构的设计过程，包括RNH-RNHI复合物的结构确定和计算分析，药物化学以及新合成抑制剂的生物化学和病毒学表征的迭代循环，来追求当前领先的改进和实现nM抗病毒活性效力。为此，我们提出三个具体目标：具体目标1。构效关系（SAR）和化学合成。我们将准备一个数据库的验证RNHI筛选命中和新的支架，我们已经开发。我们将根据目标2中的数据库分析和从晶体学和分子对接研究中获得的结构信息，对两种不同类别的RNHI进行完整的SAR。 具体目标2。RT-RNHI相互作用的晶体学和计算分析。基于结构的设计是该应用程序的主要焦点。我们将使用我们实验室已经建立的晶体学工具，这些工具通常会导致RT和/或RNH与抑制剂复合的高分辨率结构（分辨率高达1.5）。结构信息将用于指导新抑制剂的设计。 具体目标3。RNHI的生物化学和病毒学分析。我们将使用生物化学和病毒学分析来评估目标1中所选择的经验证的筛选命中和新的RNHI。这些信息将被整合到新抑制剂的迭代SAR介导的设计中。 我们的多学科方法将导致新的HIV抑制剂，对野生型和耐药病毒株都有效。 公共卫生相关性：该项目将发现针对HIV病毒基本生物活性的化合物，目前批准的药物无法解决。这些研究应该导致未来治疗方法的发展，补充现有的药物，也应该加强我们的努力，阻止艾滋病毒的耐药菌株。

DESCRIPTION (provided by applicant): Highly active antiretroviral therapy (HAART) drugs primarily target three of the four HIV enzymes: reverse transcriptase (RT) DNA polymerase, protease, and integrase. Although HAART is very effective in suppressing viral load in HIV-infected patients, prolonged treatment inevitably leads to the emergence of drug-resistant viral strains. Hence, it is essential to develop agents that act on novel HIV targets. The fourth HIV enzyme, RT- associated ribonuclease H (RNH) is one such target. RNH degrades the viral RNA genome during reverse transcription and is essential for HIV replication. It is the only enzymatic activity of HIV that has yet to be addressed by antiretroviral drugs. Such drugs will likely be active against all current drug-resistant viral strains. Our goal is to develop potent RNH inhibitors (RNHIs) with nanomolar efficacy in cell-based replication assays and for this we will use a multidisciplinary approach based on our extensive expertise in structural biology, computational biology, medicinal chemistry, enzymology, biochemistry and virology. We will pursue improvement of current leads and achievement of nM potencies of antiviral activities through a structure-based design process involving iterative cycles of structure determination and computational analysis of RNH-RNHI complexes, medicinal chemistry, and biochemical and virological characterization of newly synthesized inhibitors. To this end we propose three specific aims: Specific Aim 1. Structure-Activity Relationships (SAR) and Chemical Synthesis. We will prepare a database of the validated RNHI screening hits and novel scaffolds that we have developed. We will perform complete SAR for two different classes of RNHIs based on the database analysis and the structural information gained from crystallographic and molecular docking studies in aim 2. Specific Aim 2. Crystallographic and computational analysis of RT-RNHI interaction. Structure-based design is a main focus of this application. We will use crystallographic tools that are already established in our lab and that routinely result in high resolution structures of RT and/or RNH in complex with inhibitors (resolutions up to 1.5 ¿). The structural information will be used to guide the design of new inhibitors. Specific Aim 3. Biochemical and virologic profiling of RNHIs. We will use biochemical and virological assays to assess selected validated screening hits and new RNHIs to be prepared in Aim 1. This information will be integrated in the iterative SAR-mediated design of new inhibitors. Our multidisciplinary approach will lead to new inhibitors of HIV that will be effective against both wild- type and drug-resistant viral strains. PUBLIC HEALTH RELEVANCE: This project will discover compounds that target an essential biological activity of the HIV virus, that currently approved drugs do not address. These studies should lead to the development of future therapeutics that complement existing drugs and should also strengthen our efforts to block drug- resistant strains of HIV.