Structural Differences in SARS‐Cov‐2 Spike Proteins and their Effects

Abstract

COVID‐19 is a highly infectious disease that mainly affects the human respiratory system. Coronavirus spike glycoproteins assist in entry and infection of cells by binding to the human ACE2 receptor. Because of this, they are the main target for antibodies and inhibitors (Walls et al., 2020).Some variants of SARS‐CoV‐2 have been classified as Variants of Concern (VOCs). One characteristic of these VOCs is an “increase in transmissibility or detrimental change in COVID‐19 epidemiology” (World Health Organization, 2021) as a result of mutations in the SARS‐CoV‐2 genome. By comparing the structures of the S proteins of SARS‐CoV‐2 (Pango lineage A) and its B.1.617.2 (Delta) and B.1.1.529 (Omicron) variants using PyMOL, we studied the differences in the structure of the receptor binding domain (RBD) of these S proteins, explaining their increased binding affinity to the ACE2 receptor, and their consequent increased transmissibility. The structure of a protein is directly related to its function which is why we think that this investigation is crucial to understanding SARS‐CoV‐2 and its variants. We expect that these regions are important for studying possible impacts on vaccine effectiveness and specific drug targets for SARS‐CoV‐2.