Figure 1: Inactivation in air. The binding between the Spike protein present in the virus envelope and angiotensin-converting-enzyme receptor (ACE2) of the host cell membrane can be altered when external electric fields (EF) induce drastic conformational changes and damage in the S protein. EF impact both the prefusion state of the wild type and various variants. Local conformational changes. The secondary structure of the S protein can also be irreversibly perturbed by EF. This affects the binding to ACE2 by transforming the recognition loop L3 (responsible for a higher affinity to ACE2) from a structured to an unstructured state. The spatial arrangement of key recognition residues is completely altered, which most likely inhibits their recognition function. Global conformational changes. Electric fields are able to induce global conformational changes in the prefusion spike glycoprotein: snapshots of the studied fragment of S under an EF at 0 ns (initial thermalised stable conformation), during EF-on, and after EF-off. The major shape changes occur in the different subunits and between subunits of the S protein. No changes in the secondary structure were observed throughout the MD trajectory of the postfusion structure, despite the presence of a high-intensity field.