DDR SUBPRJ 5:FLEXIBLE PEPTIDE INHIBITORS INDUCING A STABLE CONFORMATION

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。近年来，HIV-1蛋白酶抑制剂得到了广泛的研究。然而，用抗hiv药物治疗的一个主要困难是病毒基因组的快速突变，通过改变蛋白质靶点导致对药物的耐药性。针对病毒对蛋白酶抑制剂的耐药性，已经开发出了联合疗法和鸡尾酒疗法。此外，许多耐药突变可能发生在远离活性位点的地方。这些观察结果支持了一种并非针对每种抑制剂结构的耐药性机制。相反，它们支持一种影响配体结合时蛋白酶关闭和构象变化动态过程的机制。本应用的中心假设是蛋白酶抑制剂应考虑到配体结合时发生的动态过程。本方案中的抑制剂具有“还原”肽键和中间的苯丙氨酸基团，以及两端的萘丙氨酸。我们试图通过检查这些肽的核磁共振光谱来确定它们的灵活性，并将这些抑制剂对接到HIV-1蛋白酶中进行计算分子动力学模拟来证明我们的假设。一方面，多肽具有一定的灵活性，可以适应开放构象的酶的活性位点。另一方面，过于严格的肽抑制剂将减少最佳构象的数量，并且将无法适应影响其动力学的蛋白酶中的点突变。在这项研究中积累的数据将为这项提议的长期目标奠定基础，设计更有效的抑制剂，以抵抗这种酶的突变的方式影响HIV-1蛋白酶的动力学。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Protease Inhibitors for HIV-1 protease have been developed in recent years. However, a major difficulty in the treatment with anti-HIV drugs has been the rapid mutations in the viral genome that result in resistance to the drug through changes in the protein target. Combination therapies and cocktails have developed in response to the resistance of the virus to protease inhibitors. Moreover, many resistant mutations can occur distant from the active site. These observations support a mechanism for drug resistance that is not specific to each inhibitor structure. Rather, they support a mechanism that affects a dynamic process of protease closure and conformational change upon ligand binding. The central hypothesis of this application is that the protease inhibitor should account for the dynamic process that occurs upon ligand binding. The inhibitors in this proposal have a "reduced" peptide bond and a phenylalanine group in the middle, and a naphthlylalanine on either end. We seek to prove our hypothesis through the specific aims of examining the NMR spectra of these peptides to determine their flexibility, and docking these inhibitors into HIV-1 protease performing computational molecular dynamic simulations. On the one hand, some flexibility is good in that the peptide can adapt to the active site of the enzyme in its open conformation. On the other hand, too rigid a peptide inhibitor will reduce the population of the best conformer and will be less able to adapt to the point mutations in the protease that affect its dynamics. The data accumulated in this investigation will lay the groundwork for the long range goals of this proposal to design more effective inhibitors that affect the dynamics of the HIV-1 protease in a manner that resist mutations in this enzyme.