Structure, dynamics, and function of the viroporins Vpu from HIV and p7 from HCV

描述(申请人提供)：感染人类免疫缺陷病毒(HIV)和丙型肝炎病毒(丙型肝炎病毒)是人类发病率和死亡率的最重要原因之一。在全球范围内，有4000多万人(艾滋病毒)和1.7亿人(丙型肝炎病毒)感染了这些病毒。在美国，0.6%的人口(艾滋病毒)和1.7%的人口(丙型肝炎病毒)被感染。超过25%的艾滋病毒感染者与丙型肝炎病毒混合感染(高达90%的静脉注射。吸毒者)。尽管高效抗逆转录病毒疗法取得了成功，但迫切需要开发针对新受体的全新类别的抗艾滋病毒药物，以确保不同的耐药性发展。目前丙型肝炎病毒的治疗方法严重不足，需要多种第一代抗丙型肝炎病毒药物。HIV-1和丙型肝炎病毒都有一种病毒孔蛋白，一种具有离子通道活性的小分子膜蛋白，也是潜在的药物靶点。这项拟议的研究建立在最新成果的基础上，代表着我们对膜蛋白结构研究的实质性扩展。确定HIV-1的VPU(病毒蛋白“u”)和丙型肝炎病毒的p7蛋白的结构对于了解它们的生物学活性的分子机制和发现干扰这些活性的药物是必不可少的。我们的核磁共振方法特别适合于在磷脂双层的天然环境中确定这些蛋白质的结构。由于我们的方法不受多肽分子质量的影响，因此研究同位素标记的VPU与未标记的细胞伙伴结合并不比单独研究VPU更困难。我们将探索核磁共振在VPU和P7膜结合受体研究中的应用，以确定潜在的药物结合部位。公共卫生相关性：感染人类免疫缺陷病毒(艾滋病毒)和丙型肝炎病毒(丙型肝炎病毒)是人类发病和死亡的最重要原因之一。在全球范围内，有4000多万人(艾滋病毒)和1.7亿人(丙型肝炎病毒)感染了这些病毒。在美国，0.6%的人口(艾滋病毒)和1.7%的人口(丙型肝炎病毒)被感染。超过25%的艾滋病毒感染者与丙型肝炎病毒混合感染(高达90%的静脉注射。吸毒者)。HIV是逆转录病毒科中的一种慢病毒。它通过感染CD4+T细胞和免疫系统的其他细胞而导致获得性免疫缺陷综合征(AIDS)；由此导致的免疫功能下降意味着机会性感染，如结核病和卡波西氏肉瘤，以及混合感染，如丙型肝炎病毒，对人类健康具有毁灭性的影响。HAART(高效抗逆转录病毒疗法)对许多患者有效；然而，艾滋病毒的遗传变异性意味着需要针对额外分子靶点的药物来对抗在治疗病原体基因组整合到宿主DNA的疾病过程中不可避免地产生的耐药性。拟议的研究将提供关于VPU的结构信息，VPU是病毒生命周期中的一种关键蛋白质，有可能成为治疗艾滋病药物开发的新靶点。丙型肝炎病毒是黄病毒科单链RNA病毒囊膜家族的成员，主要感染肝细胞。大多数丙型肝炎病毒感染是持续性的，并导致肝脏疾病，包括肝炎、肝硬变和肝细胞癌。因此，丙型肝炎病毒是全国肝移植的领先指标。目前丙型肝炎病毒感染的治疗方法包括聚乙二醇化干扰素和利比韦林，有许多局限性；它不仅耗时长、费用高、耐受性差，而且只在一小部分病例中有效。开发有效的抗丙型肝炎病毒药物是当务之急，特别是因为在治疗艾滋病毒和丙型肝炎病毒合并感染的患者时遇到了困难。拟议中的研究将提供关于p7的结构信息，p7是病毒生命周期中的关键蛋白，有可能成为治疗丙型肝炎药物开发的新靶点。

DESCRIPTION (provided by applicant): Infections with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are among the most significant causes of human morbidity and mortality. Worldwide, there are more than 40 million (HIV) and 170 million (HCV) people infected with these viruses. In the United States, 0.6% (HIV) and 1.7% (HCV) of the population is infected. More than 25% of those infected with HIV are co-infected with HCV (up to 90% of i.v. drug users). Despite the success of highly active anti-retroviral therapy, there is an urgent need to develop entirely new classes of anti-HIV drugs targeted to novel receptors in order to ensure different susceptibilities to the development of resistance. Current therapies for HCV are grossly inadequate, and multiple first-generation anti- HCV drugs are needed. Both HIV-1 and HCV have a viroporin, a small membrane protein with ion channel activity and a potential drug target. The proposed research builds upon recent results, and represents a substantial expansion of our structural studies of membrane proteins. Determining the structures of Vpu (Virus protein "u") from HIV-1 and the p7 protein from HCV are essential in order to understand the molecular mechanisms of their biological activities and to nucleate the discovery of drugs that interfere with these activities. Our NMR methods are particularly well suited for determining the structures of these proteins in their native environment of phospholipid bilayers. And since our approach is unaffected by the molecular mass of the polypeptides, studies of isotopically labeled Vpu bound to unlabeled cellular partners are no more difficult than for Vpu alone. We will explore the application of SAR (structure activity relationships) by NMR to Vpu and p7 as examples of membrane-bound receptors and to identify potential binding sites for drugs. PUBLIC HEALTH RELEVANCE: Infections with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are among the most significant causes of human morbidity and mortality. Worldwide, there are more than 40 million (HIV) and 170 million (HCV) people infected with these viruses. In the United States, 0.6% (HIV) and 1.7% (HCV) of the population is infected. More than 25% of those infected with HIV are co-infected with HCV (up to 90% of i.v. drug users). HIV is a lentivirus in the Retroviridae family. It causes the acquired immunodeficiency syndrome (AIDS) by infecting CD4+ T and other cells of the immune system; the resulting decline of immune functions means that opportunistic infections, such as tuberculosis and Kaposi's sarcoma, and co-infections, such as HCV, have devastating effects on human health. HAART (highly active antiretroviral therapy) is effective in many patients; however, the genetic variability of HIV means that drugs against additional molecular targets are needed to combat resistance that inevitably develops in the course of treating a disease in which the genome of the causative agent is integrated into the host DNA. The proposed studies will provide structural information about Vpu, a key protein in the viral lifecycle that has the potential to be a new target for the development of drugs to treat AIDS. HCV is a member of the Flaviviridae family of enveloped single-stranded RNA viruses that mainly infects hepatocyte. Most HCV infections are persistent and lead to liver diseases, including hepatitis, cirrhosis, and hepatocellular carcinoma. Consequently, HCV is the leading indicator for liver transplantation in the Nation. Current therapy for HCV infections consists of the administration of pegylated interferon and ribivirin and has many limitations; not only is it lengthy, expensive and poorly tolerated, but also it works in only a fraction of cases. The development of effective anti-HCV drugs is a high priority, especially because of the difficulties encountered in treating patients co-infected with HIV and HCV. The proposed studies will provide structural information about p7, a key protein in the viral lifecycle that has the potential to be a new target for the development of drugs to treat hepatitis C.