With the advent of single molecule (SM) technique, the memory effects and non-exponential kinetics originated from conformational fluctuations were emphasized in reactions of biomolecules. These deviations from the standard chemical kinetics have been already known from ensemble experiments. However, the SM measurements allow one to single out the effects of ‘dynamic disorder’ explicitly and more accurately, thereby uncovering the mechanisms of protein reactions and the control possibilities generated by structural changeability.
In early 90s we coined the concept of dynamic molecular self-organization. Its main idea is that under multiple consecutive reaction turnovers the structural memory of a macromolecule ensures the nonlinear feedback with the turnovers. As a result, the macromolecule works in a synergetic manner: depending on the intensity of the reaction initialization factor, a threshold emergence/disappearance of different functional regimes (including their coexistence, e.g. bistability) becomes possible. Experimental evidences in favour of such mode of operation have been obtained in ensemble experiments on the electron transfer reactions in the photosynthetic reaction centre [1,2]. Since these phenomena are of essentially intramolecular character, it is even more natural to expect their manifestations exactly in SM experiments where the serial occurrence of reaction turnovers takes place by definition. But how do they show up in the corresponding observables?
We propose a theoretical base and algorithms of the corresponding SM investigations capable of clearly recognizing the effects of dynamic self-organization even in the primary statistical SM characteristics (on-time distributions and autocorrelation functions) [3].