Recombinant SARS-CoV-2, S2 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. In both SARSCoV and SARSCoV2, the receptorbinding domain (RBD) is at the Cterminus of S1 and binds to the angiotensinconverting enzyme 2 (ACE2) receptor on host cells ³⁵. Following receptor binding, S1 destabilizes, and TMPRSS2 cleaves S2, which undergoes a pre to postfusion conformation transition, allowing for membrane fusion ^{4, 6}. Unlike S1, S2 is conserved among coronaviruses, and the S2 of SARSCoV2 shares 88% sequence identity with SARSCoV, suggesting that broadly neutralizing antibodies targeting S2 may crossreact with both viruses ⁴.

SVASQSIIAYTMSLGAENSVAYSNNSIAIPTNFTISVTTEILPVSMTKTSVDCTMYICGDSTECSNLLLQYGSFCTQLNRALTGIAVEQDKNTQEVFAQVKQIYKTPPIKDFGGFNFSQILPDPSKPSKRSFIEDLLFNKVTLADAGFIKQYGDCLGDIAARDLICAQKFNGLTVLPPLLTDEMIAQYTSALLAGTITSGWTFGAGAALQIPFAMQMAYRFNGIGVTQNVLYENQKLIANQFNSAIGKIQDSLSSTASALGKLQDVVNQNAQALNTLVKQLSSNFGAISSVLNDILSRLDKVEAEVQIDRLITGRLQSLQTYVTQQLIRAAEIRASANLAATKMSECVLGQSKRVDFCGKGYHLMSFPQSAPHGVVFLHVTYVPAQEKNFTTAPAICHDGKAHFPREGVFVSNGTHWFVTQRNFYEPQIITTDNTFVSGNCDVVIGIVNNTVYDPLQPELDSFKEELDKYFKNHTSPDVDLGDISGINASVVNIQKEIDRLNEVAKNLNESLIDLQELGKYEQ

Sterile Liquid

The predicted molecular mass is ~60 kDa

~60 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 Ice Pack

1. Zhou, P., Yang, X., Wang, X. et al. Nature 579, 270–273. 2020.
2. Wu, F., Zhao, S., Yu, B. et al. Nature 579, 265–269. 2020.
3. Wrapp D, Wang N, Corbett KS, et al. bioRxiv. 2020.02.11.944462. 2020.
4. Walls AC, Park YJ, Tortorici MA, et al. Cell. 181(2):281292.e6. 2020
5. Li W, Zhang C, Sui J, et al. EMBO J. 24(8):16341643. 2005.
6. Hoffmann M, KleineWeber H, Schroeder S, et al. Cell. 181(2):271280.e8. 2020.