Solitons and 1/f Noise in Molecular Chains

Davydov's model of solitons in alpha-helix protein chains is shown to display features of self-organized criticality (SOC), i.e., power law behaviour of correlations in space and 1/f-noise, as a consequence of considering random peptide group displacements from their (periodic) equilibrium positions along a chain. This may shed light on a basic mechanism leading to obtain flicker noise in alpha-helix protein chains and to predict a SOC regime in biomolecular structures from first principles. We believe our treatment of 1/f noise to be of some relevance to recent findings due to Voss on DNA [Phys. Rev. Lett. 68, 3805 (1992)].