A fractal description of the vibrational dynamics of proteins: a beautifully complicated description?

Abstract

The (Raman) spin-lattice relaxation rate T₁^-1 of a paramagnetic ion in proteins probes the vibrational dynamics of these systems. The cross-links between the various parts of the polypeptide chain playa crucial role in the dynamics. All theoretical attempts to explain the temperature dependence of T₁ as a consequence of the existence of short-range cross-links in the self-avoiding walk models of linear polymers have had, at best, very limited success. However, using a standard theoretical technique, Elber and Karplus computed T₁ for several proteins within the effective-medium approximation; the temperature dependence of T₁ was found to be in good agreement with the corresponding experimental observation.