Townsend Julia A, Fapohunda Oluwaseun, Wang Zhihan, Pham Hieu, Taylor Michael T, Kloss Brian, Park Sang Ho, Opella Stanley, Aspinwall Craig A, Marty Michael T
Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA.
New York Consortium on Membrane Protein Structure, New York Structural Biology Center, New York, NY 10027, USA.
bioRxiv. 2023 Aug 20:2023.08.18.553902. doi: 10.1101/2023.08.18.553902.
Viroporins constitute a class of viral membrane proteins with diverse roles in the viral life cycle. They can self-assemble and form pores within the bilayer that transport substrates, such as ions and genetic material, that are critical to the viral infection cycle. However, there is little known about the oligomeric state of most viroporins. Here, we use native mass spectrometry (MS) in detergent micelles to uncover the patterns of oligomerization of the full-length SARS-CoV-2 envelope (E) protein, poliovirus VP4, and HIV Vpu. Our data suggest that the E protein is a specific dimer, VP4 is exclusively monomeric, and Vpu assembles into a polydisperse mixture of oligomers under these conditions. Overall, these results revealed the diversity in the oligomerization of viroporins, which has implications for mechanisms of their biological functions as well as their potential as therapeutic targets.
病毒孔蛋白是一类病毒膜蛋白，在病毒生命周期中具有多种作用。它们可以自我组装并在双层膜内形成孔道，运输对病毒感染周期至关重要的底物，如离子和遗传物质。然而，对于大多数病毒孔蛋白的寡聚状态知之甚少。在这里，我们使用去污剂胶束中的天然质谱（MS）来揭示全长严重急性呼吸综合征冠状病毒2（SARS-CoV-2）包膜（E）蛋白、脊髓灰质炎病毒VP4和人类免疫缺陷病毒（HIV）Vpu的寡聚化模式。我们的数据表明，E蛋白是一种特定的二聚体，VP4完全是单体，在这些条件下Vpu组装成寡聚体的多分散混合物。总体而言，这些结果揭示了病毒孔蛋白寡聚化的多样性，这对其生物学功能机制及其作为治疗靶点的潜力具有重要意义。
