Flickering noise in the potential energy fluctuations of proteins as investigated by MD simulation

Long term (1.1 ns) molecular dynamics simulation on plastocyanin, an electron transport copper-containing protein, has provided evidence of 1/f noise in the potential energy fluctuations in both dry and fully hydrated states. Such behaviour, which might be traced back to the spatio-temporal features of this complex, dissipatively coupled, system displaying a multiplicity of metastable states, is analyzed also in connection with the coloured noise behaviour observed for solvent water. The possible implication in the protein folding process is briefly discussed. (C) 1997 Elsevier Science B.V.