1. Large-Scale Purification and Characterization of Recombinant Receptor-Binding Domain (RBD) of SARS-CoV-2 Spike Protein Expressed in Yeast
- Author
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Massachusetts Institute of Technology. Department of Biological Engineering, Koch Institute for Integrative Cancer Research at MIT, Massachusetts Institute of Technology. Department of Chemical Engineering, Nagar, Gaurav, Jain, Siddharth, Rajurkar, Meghraj, Lothe, Rakesh, Rao, Harish, Majumdar, Sourav, Gautam, Manish, Rodriguez-Aponte, Sergio A., Crowell, Laura E., Love, J. Christopher, Dandekar, Prajakta, Puranik, Amita, Gairola, Sunil, Shaligram, Umesh, Jain, Ratnesh, Massachusetts Institute of Technology. Department of Biological Engineering, Koch Institute for Integrative Cancer Research at MIT, Massachusetts Institute of Technology. Department of Chemical Engineering, Nagar, Gaurav, Jain, Siddharth, Rajurkar, Meghraj, Lothe, Rakesh, Rao, Harish, Majumdar, Sourav, Gautam, Manish, Rodriguez-Aponte, Sergio A., Crowell, Laura E., Love, J. Christopher, Dandekar, Prajakta, Puranik, Amita, Gairola, Sunil, Shaligram, Umesh, and Jain, Ratnesh
- Abstract
SARS-CoV-2 spike protein is an essential component of numerous protein-based vaccines for COVID-19. The receptor-binding domain of this spike protein is a promising antigen with ease of expression in microbial hosts and scalability at comparatively low production costs. This study describes the production, purification, and characterization of RBD of SARS-CoV-2 protein, which is currently in clinical trials, from a commercialization perspective. The protein was expressed in Pichia pastoris in a large-scale bioreactor of 1200 L capacity. Protein capture and purification are conducted through mixed-mode chromatography followed by hydrophobic interaction chromatography. This two-step purification process produced RBD with an overall productivity of ~21 mg/L at >99% purity. The protein’s primary, secondary, and tertiary structures were also verified using LCMS-based peptide mapping, circular dichroism, and fluorescence spectroscopy, respectively. The glycoprotein was further characterized for quality attributes such as glycosylation, molecular weight, purity, di-sulfide bonding, etc. Through structural analysis, it was confirmed that the product maintained a consistent quality across different batches during the large-scale production process. The binding capacity of RBD of spike protein was also assessed using human angiotensin-converting enzyme 2 receptor. A low binding constant range of KD values, ranging between 3.63 × 10−8 to 6.67 × 10−8, demonstrated a high affinity for the ACE2 receptor, revealing this protein as a promising candidate to prevent the entry of COVID-19 virus.
- Published
- 2023