Department of Virology, University of Freiburg, Freiburg, Germany.
Antimicrob Agents Chemother. 2011 Feb;55(2):696-702. doi: 10.1128/AAC.01419-10. Epub 2010 Dec 6.
The influenza A virus polymerase complex, consisting of the subunits PB1, PB2, and PA, represents a promising target for the development of new antiviral drugs. We have previously demonstrated the feasibility of targeting the protein-protein interaction domain between PA and PB1 using peptides derived from the extreme N terminus of PB1 (amino acids [aa] 1 to 15), comprising the PA-binding domain of PB1. To increase the binding affinity of these peptides, we performed a systematic structure-affinity relationship analysis. Alanine and aspartic acid scans revealed that almost all amino acids in the core binding region (aa 5 to 11) are indispensable for PA binding. Using a library of immobilized peptides representing all possible single amino acid substitutions, we were able to identify amino acid positions outside the core PA-binding region (aa 1, 3, 12, 14, and 15) that are variable and can be replaced by affinity-enhancing residues. Surface plasmon resonance binding studies revealed that combination of several affinity-enhancing mutations led to an additive effect. Thus, the feasibility to enhance the PA-binding affinity presents an intriguing possibility to increase antiviral activity of the PB1-derived peptide and one step forward in the development of an antiviral drug against influenza A viruses.
甲型流感病毒聚合酶复合物由 PB1、PB2 和 PA 亚基组成，是开发新型抗病毒药物的有希望的靶标。我们之前已经证明，使用源自 PB1 极端 N 端（氨基酸 [aa] 1 至 15）的肽靶向 PA 和 PB1 之间的蛋白质-蛋白质相互作用域是可行的，这些肽包含 PB1 的 PA 结合域。为了提高这些肽的结合亲和力，我们进行了系统的结构-亲和力关系分析。丙氨酸和天冬氨酸扫描表明，核心结合区域（aa 5 至 11）中的几乎所有氨基酸对于 PA 结合都是必不可少的。使用代表所有可能单个氨基酸取代的固定化肽文库，我们能够确定核心 PA 结合区域（aa 1、3、12、14 和 15）之外的氨基酸位置是可变的，可以被增强亲和力的残基取代。表面等离子体共振结合研究表明，几种增强亲和力的突变的组合导致相加效应。因此，增强 PA 结合亲和力的可行性为提高源自 PB1 的肽的抗病毒活性提供了一种有趣的可能性，并且在开发针对甲型流感病毒的抗病毒药物方面迈出了一步。
