SARS-CoV-2 protein: infrared spectroscopic investigation from Receptor Binding Domain to Spike protein

Coronaviruses are characterized by spike (S) glycoproteins, which are the largest structural membrane proteins and the first involved in the anchoring of the host receptor angiotensin-converting enzyme 2 (ACE2) through the receptor binding domain (RBD). Its secondary structure is of great interest for shedding light on various aspects, from functionality to pathogenesis, finally to spectral fingerprint for the design of optical biosensors. The aim of this work is the characterization of the whole monomeric SARS-CoV-2 S protein, its constituting components, namely RBD, S1 and S2, at serological pH (7.4) and the S1 alterations induced to chemical/physical environmental modifications by measuring their amide I absorption bands through Attenuated Total Reflectance Infrared spectroscopy (ATR-IR).