Abstract

The phenomena of molecular cooperativity involves an interaction between two or more different protein moieties in which the protein's function is controlled synergistically by its neighbor. Changes in state of the adjacent protein, such as changes in ligation of a receptor molecule, affect the reaction rate of its neighbor, often several nanometers away. The reaction rate can be controlled by either changes in the reaction free energy or activation barriers. Our current understanding of this process is based on structural changes at one site affecting the adjacent activation barrier. In order to affect a reaction coordinate at a distance, these structural changes must involve highly correlated atomic displacements coupling thousands of degrees of freedom. The key question then is what is the mechanism by which the reaction forces at one site propagate to adjacent sites, i.e., what is the communication pathway? How do the reaction forces which develop on an atomic length scale couple to mesoscopic dimensions of motion?

© 1996 Optical Society of America