Denaturation of the SARS-CoV-2 spike protein under non-thermal microwave radiation

Abstract

SARS-CoV-2, the virus that causes COVID-19, is still a widespread threat to society. The spike protein of this virus facilitates viral entry into the host cell. Here, the denaturation of the S1 subunit of this spike protein by 2.45 GHz electromagnetic radiation was studied quantitatively. The study only pertains to the pure electromagnetic effects by eliminating the bulk heating effect of the microwave radiation in an innovative setup that is capable of controlling the temperature of the sample at any desired intensity of the electromagnetic field. This study was performed at the internal human body temperature, 37 °C, for a relatively short amount of time under a high-power electromagnetic field. The results showed that irradiating the protein with a 700 W, 2.45 GHz electromagnetic field for 2 min can denature the protein to around 95%. In comparison, this is comparable to thermal denaturation at 75 °C for 40 min. Electromagnetic denaturation of the proteins of the virus may open doors to potential therapeutic or sanitation applications.

Figure 1

The sample is placed inside a microwave waveguide and connected to an efficient cooling system.

Figure 2

Stability of the temperature of the sample under high-power microwave radiation.

Figure 3

Degree of denaturation due to thermal heating of the S1 subunits compared to microwave radiation (37 °C) for each average temperature and time variable.

Figure 4

Absorption spectra of the SARS-CoV-2 spike protein S1-His recombinant subunit at average temperatures, 50, 60, and 70 °C at varying incubation times. Absorption maxima can be seen at ~ 277 nm for each.

Figure 5

UV spectra shifts of the S1 protein at 50 °C at varying incubation times. Main peak centered at ~ 256.5 nm.

Figure 6

The temperature profile of the solution in the microwave reactor under microwave irradiation. The average temperature is 37 ± 1.3 °C.

Figure 7

The simulated electric field propagation of 2.45 GHz microwave inside our waveguide. The color bar scale is arbitrary and is a measure of the electric field in V/m.