Recombinant SARS-CoV-2, NTD Protein

Severe acute respiratory syndrome coronavirus 2 (SARSCoV2), the causative agent of coronavirus disease 2019 (COVID19), is an enveloped, singlestranded, positivesense RNA virus that belongs to the Coronaviridae family ¹. The SARSCoV2 genome, which shares 79.6% identity with SARSCoV, encodes four essential structural proteins: the spike (S), envelope (E), membrane (M), and nucleocapsid protein (N) ². The S protein is a transmembrane, homotrimeric, class I fusion glycoprotein that mediates viral attachment, fusion, and entry into host cells ³. Each ~180 kDa monomer contains two functional subunits, S1 (~700 a.a) and S2 (~600 a.a), that mediate viral attachment and membrane fusion, respectively. S1 contains two major domains, the Nterminal (NTD) and Cterminal domains (CTD). In both SARSCoV and SARSCoV2, the CTD contains the receptorbinding domain (RBD), which binds to the angiotensinconverting enzyme 2 (ACE2) receptor on host cells³⁵. The NTD of SARSCoV2 does not bind to ACE2⁶, and the function of NTD in SARSCoV2 infection is not well understood. In other CoVs, the NTD may promote attachment by binding to sugar moieties⁷ and might play a role in the conformational change of S2 required for membrane fusion⁸. While most neutralizing antibodies target the RBD domain and block receptor binding, potent neutralizing antibodies targeting NTD were isolated from convalescent COVID19 patients⁹, identifying the NTD as an attractive candidate for vaccines and therapeutics. In addition, the NTD is a promising antigen for diagnostic tests, as there is only 53.5% homology between the NTD of SARSCoV2 and SARSCoV¹⁰.

VNLTTRTQLPPAYTNSFTRGVYYPDKVFRSSVLHSTQDLFLPFFSNVTWFHAIHVSGTNGTKRFDNPVLPFNDGVYFASTEKSNIIRGWIFGTTLDSKTQSLLIVNNATNVVIKVCEFQFCNDPFLGVYYHKNNKSWMESEFRVYSSANNCTFEYVSQPFLMDLEGKQGNFKNLREFVFKNIDGYFKIYSKHTPINLVRDLPQGFSALEPLVDLPIGINITRFQTLLALHRSYLTPGDSSSGWTAGAAAYYVGYLQPRTFLLKYNENGTITDAVDCALDPLSETKCTLKS

Sterile Liquid

The predicted molecular mass is ~36 kDa.

~36 kDa

This recombinant protein is aseptically packaged and formulated in 0.01 M phosphate buffered saline (PBS) pH 7.2 7.4, 150 mM NaCl with no carrier protein, potassium, calcium or preservatives added. Due to inherent biochemical properties of proteins, certain products may be prone to precipitation over time. Precipitation may be removed by aseptic centrifugation and/or filtration.

This recombinant protein may be stored as received at 28°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at 80°C. Avoid Repeated Freeze Thaw Cycles.

Next Day

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