Abstract

Functionally important motions in biological systems requires the correlated displacement of thousands of atoms. The exact mechanism for the protein response to a stimulus for the functionally relevant motions is poorly understood. The classic models for deterministic protein motion rely on potential energy gradients that are created through the interaction with a stimulus to provide the forces that orchestrate the molecular motion. The question is over what length scale are these forces distributed and what are the magnitudes of the driving force, i.e., the energetics for the structural changes. In this regard, heme proteins provide ideal systems for addressing these issues. Photodissociation of the axial ligand at the heme site selectively triggers the functionally important structural changes involved in oxygen binding and allosteric regulation of oxygen transport in heme proteins.

© 1992 The Author(s)