Utilization of Receptor-Binding Domain of SARS-CoV-2 Spike Protein Expressed in Escherichia coli for the Development of Neutralizing Antibody Assay

• DOI: 10.1007/s12033-022-00563-4
• Publication Date: 2022-09-14T10:05:20Z
• Authors: Termsak Tantiwiwat; Apisitt Thaiprayoon; Ake-kavitch Siria...; Chakrit Tachaapai...; Nongluk Plongthon...; Dujduan Waraho-Zh...
• Keywords: HEK 293 cells; Ligand binding assay; Competitive binding

The ongoing COVID-19 pandemic has resulted from widespread infection by the SARS-CoV-2 virus. As new variants of concern continue to emerge, understanding correlation between level neutralizing antibodies (NAb) and clinical protection SAR-CoV-2 could be critical in planning next steps vaccine programs. This study explored potential usefulness E. coli as an alternative expression system that can used produce a receptor-binding domain (RBD) for development affordable flexible NAb detection assay. We expressed RBD Beta, Delta, Omicron BL21(DE3) strain purified them whole bacterial cells using His-tag-mediated affinity chromatography urea-assisted refolding. Next, we conducted head-to-head comparison binding activity our coli-produced (E-RBD) with commercial HEK293-produced (H-RBD). results direct assay revealed E-RBD H-RBD ACE2-hFc similar signal strengths. Furthermore, assay, % inhibition obtained both demonstrated comparable all investigated assays, suggesting non-glycosylated produced may offer cost-effective use more expensive glycosylated human such