The dynamics of an alpha-helical protein chain with quintic nonlinearity are described in this article by identifying a perfectly integrable model. Using Hirota’s bilinearisation technique, we analyse the dynamics in the continium limit and study the solitonic feature of the system by developing multi-soliton solutions to the resultant completely integrable two-dimensional protein system. In the Inhomogeneous situation, we use a perturbation technique to investigate the stability of solitons and we find the center of mass and velocity of the soliton.