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 continuum limit and study the solitonic feature of the system by developing multisoliton solutions to the resultant completely integrable two-dimensional protein system. In the Inhomogeneous sitiuation, we use a peturbation technique to investigate the stability of solitons and we find the center of mass and velocity of the soliton.