Influence of induced excitation on the functionality of a finite-length segment of the molecular chain

This study investigates the possibility that an injected intramolecular excitation, which becomes self-trapped due to its interaction with thermal oscillations of the molecular chain, can influence the chain’s functionality in physiological processes in which it eventually participates. Quantum resonance effects may cause the excitation, initially induced at one structural element, to delocalize and reappear at a distant site. To explore this phenomenon, we developed and analyzed a theoretical model in which a single excitation is injected into a specific structural element of a finite-length segment of the molecular chain. It was assumed that the molecular chain consists of several segments connected in such a way that the excitation, which is excited within one segment, cannot pass to another one. Finally, it was assumed that the molecular chain is in thermal equilibrium with its environment. Differential equations for the correlation functions were derived and solved analytically, providing the probability of finding the excitation at each site. The obtained results indicate that injected excitation can affect the function of the biomolecule, especially at higher temperatures, when the excitation residence time on a molecular node becomes long enough to affect the functionality of the local segment of the biomolecule. In addition, the position of the initially excited node can lead to the emergence of an asymmetric probability distribution with respect to the initial site, resulting in an effective “directed” migration of the excitation.