Structural basis for influenza amantadine-resistance

流感金刚烷胺耐药的结构基础

• 批准号: 7148115
• 负责人: JAMES Jeiwen CHOU
• 金额: $ 33.9万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-07-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7148115
• 关键词: amantadine; influenza

DESCRIPTION (provided by applicant): The influenza pandemics have long been a serious global health threat responsible for approximately 20,000 deaths per year in the US. It has been established that small H+ selective channels M2 and BM2 from influenza A and B virus play a critical role in viral replication and thus are effective targets for anti-influenza therapy. Amantadine is a licensed anti-influenza A drug that functions by inhibiting the pH activation of the M2 channel. However a number of M2 variants, as well as the BM2 channel of influenza B can escape the effect of amantadine, leading to the amantadine-resistance of these viruses. We propose to provide the atomic details of H+ gating and drug interaction of these small channels for understanding the mechanisms by which some influenza strains are resistant to amantadine. Initially we will solve the high resolution structure of the M2 H+ channel of influenza A virus in the closed state at pH 7.2. A new method has been devised to facilitate structure determination by solution NMR, which incorporates the dipolar couplings for acquiring orientation parameters and lipid/detergent bilayered micelles to enable characterization of atomic structures in a near lipid-bilayer environment. We will also solve the channel structure in the open state at pH 5.2 to delineate changes in conformation and dynamics that are coupled to low-pH activation. To understand the mechanism of amantadine inhibition, we will solve the channel structures, both closed and open, in the presence of drug binding. The sites of amantadine interaction in the channel will also be located. In parallel, the structures of the known amantadine-resistant variants of M2 will be examined for direct comparison to elucidate mechanisms of channel blocking. Similar studies will be done for the BM2 channel, which functions similarly to M2 but is resistant to amantadine. Structural details of the potential amantadine-BM2 interaction that does not block the channel will also be explored. The results will lay a solid foundation for our long- range goal of finding a true blocker of H+ channels for anti-influenza treatment.

描述（由申请人提供）：流感大流行长期以来一直是严重的全球健康威胁，每年在美国造成约20，000人死亡。已经确定来自甲型和B型流感病毒的小H+选择性通道M2和BM 2在病毒复制中起关键作用，因此是抗流感治疗的有效靶标。金刚烷胺是一种获得许可的抗甲型流感药物，通过抑制M2通道的pH激活发挥作用。然而，许多M2变体以及B型流感的BM 2通道可以逃避金刚烷胺的作用，导致这些病毒的金刚烷胺抗性。我们建议提供这些小通道的H+门控和药物相互作用的原子细节，以了解某些流感病毒株对金刚烷胺耐药的机制。首先，我们将解决在pH 7.2的封闭状态下甲型流感病毒的M2 H+通道的高分辨率结构。已经设计了一种新的方法，以促进结构测定的溶液NMR，它结合了偶极耦合获得取向参数和脂质/洗涤剂双层胶束，使表征的原子结构在近脂质双层环境。我们还将解决在pH值为5.2的开放状态下的通道结构，以描绘与低pH值激活耦合的构象和动力学变化。为了了解金刚烷胺抑制的机制，我们将解决在药物结合存在下的通道结构，包括封闭和开放。还将定位通道中金刚烷胺相互作用的位点。同时，将检查已知的M2金刚烷胺耐药变体的结构，以进行直接比较，阐明通道阻断机制。将对BM 2通道进行类似的研究，该通道的功能与M2相似，但对金刚烷胺具有耐药性。还将探索不阻断通道的潜在金刚烷胺-BM 2相互作用的结构细节。该结果将为我们寻找真正的H+通道阻断剂用于抗流感治疗的长期目标奠定坚实的基础。