Abstract
The currently devastating pandemic of severe acute respiratory syndrome known as coronavirus disease 2019 or COVID-19 is caused by the coronavirus SARS-CoV-2. Both the virus and the disease have been extensively studied worldwide. A trimeric spike (S) protein expressed on the virus outer bilayer leaflet has been identified as a ligand that allows the virus to penetrate human host cells and cause infection. Its receptor-binding domain (RBD) interacts with the angiotensin-converting enzyme 2 (ACE2), the host-cell viral receptor, and is, therefore, the subject of intense research for the development of virus control means, particularly vaccines. In this work, we search for smaller fragments of the S protein able to elicit virus-neutralizing antibodies, suitable for production by peptide synthesis technology. Based on the analysis of available data, we selected a 72 aa long receptor binding motif (RBM 436-507 ) of RBD. We used ELISA to study the antibody response to each of the three antigens (S protein, its RBD domain and the RBM 436-507 synthetic peptide) in humans exposed to the infection and in immunized mice. The seroreactivity analysis showed that anti-RBM antibodies are produced in COVID-19 patients and immunized mice and may exert neutralizing function, although with a frequency lower than anti-S and -RBD. These results provide a basis for further studies towards the development of vaccines or treatments focused on specific regions of the S virus protein, which can benefit from the absence of folding problems, conformational constraints and other advantages of the peptide synthesis production.
Keywords: COVID-19; SARS-CoV-2; immunized animals; neutralizing Abs; receptor binding motif; spike (S) protein.
【저자키워드】 COVID-19, SARS-CoV-2, receptor binding motif, neutralizing Abs, spike (S) protein., immunized animals, 【초록키워드】 Treatment, coronavirus disease, ACE2, Vaccine, pandemic, Vaccines, S protein, antibody, Human, Infection, peptide, virus, coronavirus SARS-CoV-2, angiotensin-converting enzyme 2, ELISA, Antigen, Protein, Region, RBD, Research, Neutralizing, receptor, Ligand, Frequency, Analysis, Receptor binding, COVID-19 patient, RBD domain, acute respiratory syndrome, available data, problems, subject, domain, virus-neutralizing antibodies, anti-S, trimeric spike, immunized mice, neutralizing function, means, benefit, immunized, selected, produced, caused, the disease, absence, expressed, interact, elicit, conformational, the S protein, the antibody response, human host cell, penetrate, peptide synthesis, RBM, 【제목키워드】 spike,