Soliton dynamics in the helix polypeptide chains

The coupling model between the three hydrogen-bonded chains to describe the helix polypeptide chain is investigated. The kink group, envelope-soliton and breather groups are obtained, in which the symmetric and asymmetric kink groups correspond to the local contraction (or expansion) and twisting deformed regions of helix polypeptide chain, respectively. The piezoelectric stress coefficient to describe the piezoelectric phenomenon arising from the local twisting deformation of the helix polypeptide chain is defined. The symmetric breather group will occur in the dipole radiation. The motion of asymmetric envelope-soliton group will result in the wriggle of the helix polypeptide chain, just like that of an earthworm. We show that (i) the twisting deformed structure of the helix polypeptide chain is more stationary than the uniform helix structure. (ii) The piezoelectric effect of collagen fibril of bone originates from the piezoelectricity of the helix polypeptide chain. (iii) The static attraction between the intrinsical charges arising from deformation of the helix polypeptide chain is advantageous to fold protein chain into the tertiary structure. A “gear model” ( or “molecule motor model”) to explain the mechanism of muscle contraction is suggested.