Influence of heat bath and disorder in the sequence of amino acid masses on Davydov solitons

The theory of Davydov solitons for the energy transport in proteins is briefly summarised, using for the dynamics of the solitons the quantum equations of motion. To obtain a more realistic model for the internal thermal motion of the protein lattice, a temperature of 300 K is considered. Since the 20 natural amino acids have different masses, disorder in the mass sequence is discussed. The soliton remains remarkably stable against thermal motions as well as against mass variation at one site. Also, a random sequence of masses destroys the soliton only for a very large deviation from the average mass.