Sci Rep. 2025 Nov 28.
The natural vibrational frequencies of biological particles encode critical information about their structures and properties. The natural vibrational frequencies have been explored for early detection and inactivation of viruses. The resonant frequency-based biophysical methods present an interesting alternative to traditional vaccine and drug treatment against the spread and infection of pathogenic viruses. However, measuring natural vibrational frequencies of a single virion in a biological environment is challenging. Assigning structural features to measured spectra is even more difficult. We have simulated the dynamic motion of SARS-CoV-2 spike protein using all-atom molecular dynamics simulation. A resonance frequency at 7.3-7.4 GHz has been identified. The finding provides a molecular-level theoretical basis for attributing the experimentally observed SARS-CoV-2 microwave absorption peak at ~ 7.5 GHz to the intrinsic vibration of the spike protein, which is different from the previously proposed viral shell-core dipole model.