Al-Mawsawi Laith Q, Hombrouck Anneleen, Dayam Raveendra, Debyser Zeger, Neamati Nouri
Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA.
Virology. 2008 Aug 1;377(2):355-63. doi: 10.1016/j.virol.2008.04.030. Epub 2008 Jun 2.
HIV-1 integrase (IN) is an essential enzyme for viral infection. Here, we report an extensive pi electron orbital interaction between four amino acids, W132, M178, F181 and F185, located at the dimeric interface of IN that is critical for the strand transfer activity alone. Catalysis of nine different mutant IN proteins at these positions were evaluated. Whereas the 3'-processing activity is predominantly strong, the strand transfer activity of each enzyme was completely dependent on an intact pi electron orbital interaction at the dimeric interface. Four representative IN mutants were constructed in the context of the infectious NL4.3 HIV-1 viral clone. Whereas viruses with an intact pi electron orbital interaction at the IN dimeric interface replicated comparable to wild type, viruses containing an abolished pi interaction were non-infectious. Q-PCR analysis of viral DNA forms during viral replication revealed pleiotropic effects of most mutations. We hypothesize that the pi interaction is a critical contact point for the assembly of functional IN multimeric complexes, and that IN multimerization is required for a functional pre-integration complex. The rational design of small molecule inhibitors targeting the disruption of this pi-pi interaction should lead to powerful anti-retroviral drugs.
HIV-1整合酶（IN）是病毒感染所必需的一种酶。在此，我们报告了位于IN二聚体界面的4个氨基酸W132、M178、F181和F185之间广泛的π电子轨道相互作用，该相互作用仅对链转移活性至关重要。对这些位置的9种不同突变型IN蛋白的催化作用进行了评估。虽然3'-加工活性主要较强，但每种酶的链转移活性完全依赖于二聚体界面处完整的π电子轨道相互作用。在具有感染性的NL4.3 HIV-1病毒克隆背景下构建了4种代表性的IN突变体。在IN二聚体界面具有完整π电子轨道相互作用的病毒与野生型病毒复制能力相当，而π相互作用被消除的病毒则无感染性。对病毒复制过程中病毒DNA形式的Q-PCR分析揭示了大多数突变的多效性作用。我们推测π相互作用是功能性IN多聚体复合物组装的关键接触点，并且功能性整合前复合物需要IN多聚化。针对破坏这种π-π相互作用进行小分子抑制剂的合理设计应能产生强效抗逆转录病毒药物。
