COVID-19 Spike E-Mosaic Protein

Source : Escherichia Coli. The E.Coli derived recombinant protein contains the Coronavirus 2019 spike E-Mosaic immunodominant regions, fused to His tag at C-termin. A human infecting coronavirus (viral pneumonia) called 2019 novel coronavirus, 2019-nCoV was found in the fish market at the city of Wuhan, Hubei province of China on December 2019. The 2019-nCoV shares an 87% identity to the 2 bat-derived severe acute respiratory syndrome 2018 SARS-CoV-2 located in Zhoushan of eastern China. 2019-nCoV has an analogous receptor-BD-structure to that of 2018 SARS-CoV, even though there is a.a. diversity so thus the 2019-nCoV might bind to ACE2 receptor protein (angiotensin-converting enzyme 2) in humans. While bats are possibly the host of 2019-nCoV, researchers suspect that animal from the ocean sold at the seafood market was an intermediate host. RSCU analysis proposes that the 2019-nCoV is a recombinant within the viral spike glycoprotein between the bat coronavirus and an unknown coronavirus. Protein function: [Spike protein S1]: Attaches the virion to the cell membrane by interacting with host receptor, initiating the infection. Binding to human ACE2 receptor and internalization of the virus into the endosomes of the host cell induces conformational changes in the Spike glycoprotein (PubMed:32142651, PubMed:32221306, PubMed:32075877, PubMed:32155444). Binding to host NRP1 and NRP2 via C-terminal polybasic sequence enhances virion entry into host cell (PubMed:33082294, PubMed:33082293). This interaction may explain virus tropism of human olfactory epithelium cells, which express high level of NRP1 and NRP2 but low level of ACE2 (PubMed:33082293). The stalk domain of S contains three hinges, giving the head unexpected orientational freedom (PubMed:32817270). Uses human TMPRSS2 for priming in human lung cells which is an essential step for viral entry (PubMed:32142651). Can be alternatively processed by host furin (PubMed:32362314). Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membrane fusion within endosomes. [The UniProt Consortium]