Novel Protein Expression and Purification of SARS CoV-2 from Recombinant Escherichia coli System

Introduction: The SARS-CoV-2 epidemic has infected and killed millions of people worldwide since 2019. Therapies available for SARS-CoV-2 disease are limited due to the sudden emergence of the virus. The need for appropriate vaccines to combat this dangerous virus is essential. Induction of specific antibodies against SARS-CoV-2 virus is mainly by nucleocapsid (N), membrane (M) and spike glycoprotein (S) proteins. On the other hand, cost-effective and fast methods for the expression and purification of recombinant proteins that retain antigenic properties are essential for vaccine development. Methods: A DNA fragment encoding the N, M and S1 proteins was inserted into pET28a vector to make an expression plasmid. The recombinant protein was then expressed in Escherichia coli Rosetta strain and purified by Ni-NTA column, followed by confirmation by SDS-PAGE and Western blotting. Results: PCR results showed that the gene was inserted correctly into the expression vector. The expression of the recombinant protein containing N, M and S1 proteins from SARS CoV-2 was optimized in a bacterial system. The recombinant protein was successfully purified from Ni-NTA column with a high yield Conclusion: Upon further evaluations, this cost-effective approach for the production of recombinant antigenic proteins in E. coli (Rosetta), could potentially be used for the development of vaccines against coronaviruses infections.