Motor-Free Locomotion of Influenza A through Complex Glycan Landscapes

Can nanoscale particles navigate complex environments without internal machinery? Influenza A viruses cross dense, sialylated host barriers by coupling multivalent adhesion to localized catalysis through its surface proteins, Hemagglutinin (HA) and neuraminidase (NA). HA binds sialic-acid receptors; NA removes them. This pairing breaks time-reversal symmetry and turns local molecular events into mesoscale transport. Using stochastic simulations and mean-field modeling, we identify a "Goldilocks" window: HA–SA binding strong enough to read receptor patterns yet weak enough to permit release, suggesting evolutionary tuning to host barriers. On uniform receptor carpets, NA creates receptor-depleted wakes that suppress backtracking, yielding superdiffusive motion. When receptor density varies, experiments show directional bias toward higher-density regions; simulations recapitulate the response. HA/NA surface protein organization further modulates motion: in wildtype filamentous virions with polarized HA/NA, front-loaded HA samples the forward field while trailing NA edits the wake, enhancing persistence and directional response without any internal signaling mechanism. Coordinating binding, catalysis, and polarity generates non-equilibrium navigation on glycan landscapes and suggests design rules for motor-free, environment-powered transport of nanoscale entities.