SARS-CoV-2 is an enveloped positive-sense single-stranded RNA virus of the Coronavirus family. First identified in Wuhan Province, China in December 2019 as the etiological agent of the COVID-19 disease, SARS-CoV-2 was soon classified as a pandemic strain that likely originated in animal reservoirs (zoonotic origin ). The genome of the strain was obtained shortly, allowing the design of rapid response platforms for diagnosis and vaccine/biotherapeutic development. Like SARS-CoV-1, the new strain was found to adhere to human epithelial cells through its transmembrane structural protein known as the spike protein.
The peak, one of the most abundant structural proteins in the envelope of this virus, is a complex and trimeric structure that contains an N-terminal domain (S1 subunit) responsible for binding the human ACE2 receptor and a C-terminal domain (S2 subunit). ) responsible for forming the fusion core that mediates membrane fusion and viral internalization. The two units are linked by a furin cleavage site readily cleaved by ubiquitous proteases. This property has made the production of stable full-length forms of the peak protein quite challenging.
Several strategies can be used to overcome this limitation, in ProteoGenix, the full-length recombinant peak protein of SARS-CoV-2 was stabilized before its expression with mutations directed to the furin cleavage site, considerably increasing its useful life without altering. its original value. function. Thus, the stabilized variant can be used for studies that aim to further unravel the mechanism of infection in this new strain, but also serve in the development of diagnostic tools, targeted treatments, and vaccines.
The D614 variant of the peak was the dominant form of the protein during the first months of the epidemic when a sudden mutation in early March caused this position to begin to gain relevance (D614G, corresponding to a GAA base change at position 23,403 in the Wuhan reference strain). The data shows that the G614 variant, also known as the “G” clade, was first detected in Europe and then spread around the world to become the dominant variant for a single month. In this context, the original D614 remains useful for comparative studies and further clarification of the mechanisms of SARS-CoV-2 infection.