{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T23:40:40Z","timestamp":1790811640244,"version":"4.1.0"},"reference-count":60,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T00:00:00Z","timestamp":1625702400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:p>Severe acute respiratory syndrome coronavirus (SARS-CoV), an enveloped single-stranded positive-sense RNA virus, is a member of the genus<jats:italic>Betacoronavirus<\/jats:italic>, family Coronaviridae. The SARS-CoV envelope protein E is a small (\u223c8.4 kDa) channel-forming membrane protein whose sequence is highly conserved between SARS-CoV and SARS-CoV-2. As a viroporin, it is involved in various aspects of the virus life cycle including assembly, budding, envelope formation, virus release, and inflammasome activation. Here, SARS-CoV E protein was recombinantly expressed in HEK293 cells and channel activity and the effects of viroporin inhibitors studied using patch-clamp electrophysiology and a cell viability assay. We introduced a membrane-directing signal peptide to ensure transfer of recombinant E protein to the plasma membrane. E protein expression induced transmembrane currents that were blocked by various inhibitors. In an ion-reduced buffer system, currents were proton-dependent and blocked by viroporin inhibitors rimantadine and amantadine. I-V relationships of recombinant E protein were not pH-dependent in a classical buffer system with high extracellular Na<jats:sup>+<\/jats:sup>and high intracellular K<jats:sup>+<\/jats:sup>. E-protein mediated currents were inhibited by amantadine and rimantadine, as well as 5-(N,N-hexamethylene)amiloride (HMA). We tested a total of 10 flavonoids, finding inhibitory activity of varying potency. Epigallocatechin and quercetin were most effective, with IC<jats:sub>50<\/jats:sub>values of 1.5 \u00b1 0.1 and 3.7 \u00b1 0.2 nM, respectively, similar to the potency of rimantadine (IC<jats:sub>50<\/jats:sub>= 1.7 \u00b1 0.6 nM). Patch-clamp results were independently verified using a modified cell viability assay for viroporin inhibitors. These results contribute to the development of novel antiviral drugs that suppress virus activity and proliferation.<\/jats:p>","DOI":"10.3389\/fmicb.2021.692423","type":"journal-article","created":{"date-parts":[[2021,7,8]],"date-time":"2021-07-08T12:40:06Z","timestamp":1625748006000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":46,"title":["Inhibition of SARS CoV Envelope Protein by Flavonoids and Classical Viroporin Inhibitors"],"prefix":"10.3389","volume":"12","author":[{"given":"Ulrike","family":"Breitinger","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nourhan K. 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