Multisoliton solutions and stability aspects of higher order discrete nonlinear Schrödinger equation governing protein dynamics

We propose a discrete model of alpha-helical proteins by taking into account dipole and quadrupole type molecular excitations. The interaction properties of multisolitons are studied both analytically and numerically. We investigate the conditions for the modulation instability (MI) of plane waves and hence the formation of localized structures in the system and show that discreteness drastically change the conditions for MI under different physical situations.