Stationary and moving breathers in a simplified model of curved alpha-helix proteins

We study the existence, stability and movability of breathers in a model for alpha-helix proteins. This model basically consists of a chain of dipole moments parallel to it. The existence of localized linear modes means that the system has a characteristic frequency, which depends on the curvature of the chain. Hard breathers are stable, while soft breathers experience subharmonic instabilities that are preserved, whatever the localization. Moving breathers can travel across the bending point for small curvature and are reflected when it is increased. No trapping of breathers takes place.