Structure and drug binding of the SARS-CoV-2 envelope protein transmembrane domain in lipid bilayers
NATURE STRUCTURAL & MOLECULAR BIOLOGY
Authors: Mandala, Venkata S.; McKay, Matthew J.; Shcherbakov, Alexander A.; Dregni, Aurelio J.; Kolocouris, Antonios; Hong, Mei
Abstract
An essential protein of the SARS-CoV-2 virus, the envelope protein E, forms a homopentameric cation channel that is important for virus pathogenicity. Here we report a 2.1-angstrom structure and the drug-binding site of E's transmembrane domain (ETM), determined using solid-state NMR spectroscopy. In lipid bilayers that mimic the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) membrane, ETM forms a five-helix bundle surrounding a narrow pore. The protein deviates from the ideal alpha-helical geometry due to three phenylalanine residues, which stack within each helix and between helices. Together with valine and leucine interdigitation, these cause a dehydrated pore compared with the viroporins of influenza viruses and HIV. Hexamethylene amiloride binds the polar amino-terminal lumen, whereas acidic pH affects the carboxy-terminal conformation. Thus, the N- and C-terminal halves of this bipartite channel may interact with other viral and host proteins semi-independently. The structure sets the stage for designing E inhibitors as antiviral drugs. A solid-state NMR structure of the transmembrane domain from SARS-CoV-2 envelope protein in the phospholipid environment reveals determinants of cation selectivity, a dehydrated pore and an N-terminal drug-binding site.
Virus Irradiation and COVID-19 Disease
FRONTIERS IN PHYSICS
Authors: Durante, Marco; Schulze, Kai; Incerti, Sebastien; Francis, Ziad; Zein, Sara; Guzman, Carlos Alberto
Abstract
Virus irradiation has been performed for many decades for basic research studies, sterilization, and vaccine development. The COVID-19 outbreak is currently causing an enormous effort worldwide for finding a vaccine against coronavirus. High doses of gamma-rays can be used for the development of vaccines that exploit inactivated virus. This technique has been gradually replaced by more practical methods, in particular the use of chemicals, but irradiation remains a simple and effective method used in some cases. The technique employed for inactivating a virus has an impact on its ability to induce an adaptive immune response able to confer effective protection. We propose here that accelerated heavy ions can be used to inactivate SARS-CoV-2 viruses with small damage to the spike proteins of the envelope and can then provide an intact virion for vaccine development.