Expression in E. coli and Characterization of a recombinant form of the SARS-COV-2 Virus Receptor Binding Domain

Abstract

Following the outbreak of the COVID19 pandemic caused by the SARS-Cov-2 corona virus, it became urgent to understand the immune response to this emergent new virus. Therefore, it is important to develop Biological Tools for the investigation of the human immune response to this viral infection. The development of such tools requires the availability of large number of viral antigens. The present study is the first step for developing the production of one of SARS COV-2 major antigens namely, the virus Receptor Binding Domain [S-RBD], which is a structural entity of the Spike protein that the virus uses to recognize and infect the host cells. The bacterial strain Escherichia Coli was used to produce a recombinant form of the SARS CoV-2 RBD domain protein that can ultimately be used to investigate the antiviral Humoral immune response. For detecting and quantifying our protein, an Indirect ELISA assay was used. Our results suggest a positive binding of S-RBD antigen with antibodies in the Serum. The highest concentration of antigen was found to be detected in the sample of the vaccinated people (OD equal to 0.7). On the other hand, control samples were showing a low signal background (OD equal to 0.3)