INFRARED SPECTROSCOPY INVESTIGATION OF SARS-COV-2 SPIKE PROTEIN DOMAINS

Here, we performed a study on the S1 (variant of March 2020) subunit under pH 7.4 and temperature variations, observing how the S1 protein adapts its secondary structure to different inhospitable surroundings. The high stable configuration is present at endosomal pH 5.5 and at temperature of 30°C, proving that the protein evolution modifications yield the protein more performant. Furthermore, we perform a comparison of IR spectroscopic secondary structure analyses of the S1 monomer of three SARS-CoV-2 variants, showing how IR technique allows their discrimination. Experimental data in combination with MultiFOLD predictions, Define Secondary Structure of Proteins (DSSP) web server (DSSP) and Gravy value calculations, provide a comprehensive understanding of proteins’ domains in terms of their secondary structure content, conformational order and interaction with the solvent.