RE: S protein8 Dec 2021 20:52
Our test works when the virus is active and affimers bind in the region of the spikes not with the spikes. The N protein on its own is not infectious as it is spikes that attach to a host target and the N protein is not necessarily present in an active infection whereas the S protein when on the envelope of the active virus is the infectious virus stage which the AffiDX® SARS-CoV-2 Antigen Lateral Flow Test is designed to detect.
Virus Genomic Structure
The current COVID-19 pandemic is caused by the novel coronavirus strain SARS-CoV-2, a positive-sense, single-stranded enveloped RNA belonging to the Coronaviridae family12 (Figure 1A). The SARS-CoV-2 genome is >30 kb in length and consists of 14 open reading frames (ORFs) encoding 27 proteins.13 The 5' end of the SARS-CoV-2 genome consists of ORF1a/b encoding a polyprotein that is post-translationally cleaved into 16 non-structural proteins (nsp1–16), which form the replicase/transcriptase complex (RTC). This complex contains enzymes involved in the replication mechanism, including papain-like protease (nsp3), main protease (nsp5), nsp7-nsp8 primase complex, primary RNA-dependent RNA polymerase (RdRp; nsp12), helicase/triphosphatase (nsp13), exoribonuclease (nsp14), endonuclease (nsp15), and N7- and 2'-O-methyltransferases (nsp10/nsp16). The 3' terminus of the viral genome contains ORFs encoding the four main structural proteins, spike (S), envelope (E), membrane (M), and nucleocapsid (N), as well as nine putative accessory factors (Figure 1B).14,15https://www.dovepress.com/cr_data/article_fulltext/s306000/306441/img/IDR_A_306441_O_F0001g.jpg