Polymer modification of SARS-CoV-2 spike protein impacts its ability to bind key receptor.

The global spread of SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) has caused the loss of many human lives and severe economic losses. SARS-CoV-2 mediates its infection in humans via the spike glycoprotein. The receptor binding domain of the SARS-CoV-2 spike protein binds to its cognate receptor, angiotensin converting enzyme-2 (ACE2) to initiate viral entry. In this study, we examine how polymer modification of the spike protein receptor binding domain impacts binding to ACE2. The horseradish peroxidase conjugated receptor binding domain was modified with a range of polymers including hydrophilic N,N -dimethylacrylamide, hydrophobic N -isopropylacrylamide, cationic 3-( N,N -dimethylamino)propylacrylamide, and anionic 2-acrylamido-2-methylpropane sulfonic acid polymers. The effect of polymer chain length was observed using N,N -dimethylacrylamide polymers with degrees of polymerization of 5, 10 and 25. Polymer conjugation of the receptor binding domain significantly reduced the interaction with ACE2 protein, as determined by an enzyme-linked immunosorbent assay. Stability analysis showed that these conjugates remained highly stable even after seven days incubation at physiological temperature. Hence, this study provides a detailed view of the effect specific type of modification using a library of polymers with different functionalities in interrupting RBD-ACE2 interaction.
Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dominik Konkolewicz reports was provided by National Science Foundation. Richard C Page reports financial support was provided by National Science Foundation. Monica Rahman reports financial support was provided by National Science Foundation. Nethmi De Alwis Watuthanthrige reports was provided by National Science Foundation. Dominik Konkolewicz reports financial support was provided by Miami University. Richard C. Page reports financial support was provided by Miami University.
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