Reshaping and enzymatic activity may allow viruses to move through the mucus

Area of Science:

• Biophysics
• Virology
• Soft Matter Physics

Background:

• Filamentous viruses, including influenza and torovirus, exhibit unexplained bends and arcs.
• The physical mechanisms driving viral morphology and movement remain incompletely understood.

Purpose of the Study:

• To propose a physical model explaining the spontaneous curvature in filamentous viruses.
• To investigate the role of viral surface proteins and interactions in inducing viral shape changes.
• To explore how enzymatic activity can lead to viral propulsion.

Main Methods:

• Theoretical modeling of elastic instabilities in cylindrical filaments.
• Analysis of spontaneous symmetry breaking and soft mode propagation.
• Investigating non-equilibrium enzymatic reactions on viral surfaces.

Main Results:

• Filamentous viruses can undergo a toro-elastic instability, transitioning from a cylindrical to a toroidal state.
• Spike protein interactions and surface topography contribute to prestress, triggering buckling.
• Enzymatic cleavage of host glycans can induce rotation and propulsion of the virus.

Conclusions:

• The toro-elastic instability provides a physical basis for viral curvature.
• Enzymatic activity on host molecules can drive viral motility, distinct from known mechanisms.
• This mechanism offers new insights into viral dynamics and host-pathogen interactions.