Characterization of the SARS-CoV-2 S Protein: Biophysical, Biochemical, Structural, and Antigenic Analysis.Herrera, N.G., Morano, N.C., Celikgil, A., Georgiev, G.I., Malonis, R.J., Lee, J.H., Tong, K., Vergnolle, O., Massimi, A.B., Yen, L.Y., Noble, A.J., Kopylov, M., Bonanno, J.B., Garrett-Thomson, S.C., Hayes, D.B., Bortz, R.H., Wirchnianski, A.S., Florez, C., Laudermilch, E., Haslwanter, D., Fels, J.M., Dieterle, M.E., Jangra, R.K., Barnhill, J., Mengotto, A., Kimmel, D., Daily, J.P., Pirofski, L.A., Chandran, K., Brenowitz, M., Garforth, S.J., Eng, E.T., Lai, J.R., Almo, S.C.
- PubMed: 32587972
- DOI: 10.1101/2020.06.14.150607
- Primary Citation of Related Structures:
- PubMed Abstract:
Coronavirus disease 2019 ( COVID-19 ) is a global health crisis caused by the novel severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ), and there is a critical need to produce large quantities of high-quality SARS-CoV-2 Spike ( S ) protein for use in both clinical and basic science settings ...
Coronavirus disease 2019 ( COVID-19 ) is a global health crisis caused by the novel severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ), and there is a critical need to produce large quantities of high-quality SARS-CoV-2 Spike ( S ) protein for use in both clinical and basic science settings. To address this need, we have evaluated the expression and purification of two previously reported S protein constructs in Expi293F ™ and ExpiCHO-S ™ cells, two different cell lines selected for increased expression of secreted glycoproteins. We show that ExpiCHO-S ™ cells produce enhanced yields of both SARS-CoV-2 S proteins. Biochemical, biophysical, and structural ( cryo-EM ) characterization of the SARS-CoV-2 S proteins produced in both cell lines demonstrate that the reported purification strategy yields high quality S protein (non-aggregated, uniform material with appropriate biochemical and biophysical properties). Importantly, we show that multiple preparations of these two recombinant S proteins from either cell line exhibit identical behavior in two different serology assays. We also evaluate the specificity of S protein-mediated host cell binding by examining interactions with proposed binding partners in the human secretome. In addition, the antigenicity of these proteins is demonstrated by standard ELISAs, and in a flexible protein microarray format. Collectively, we establish an array of metrics for ensuring the production of high-quality S protein to support clinical, biological, biochemical, structural and mechanistic studies to combat the global pandemic caused by SARS-CoV-2.
Department of Biochemistry, Virginia Tech, Blacksburg, Virginia 24061, USA.