[Transformation of chemical energy in biomolecular systems with hydrogen bonds]

The mechanism underlying the excitation of the hydrogen bond with ATP hydrolysis was considered. Coulomb interactions of the proton of the hydrogen bond A-H...B with the electrical field of the covalent bond of ADP-P were calculated. It was shown that the electrical field of the covalent bond of ADP-P excites oscillations of the proton in the complex with the hydrogen bond A-H...B and displaces it from the equilibrium towards the covalent bond. The distortion of the potential curve depends on a change in the length of the covalent bond of ADP-P. Adiabatic potentials U0 and UN of the ADP-P system were calculated, which correspond to the ground and excited states of the H-bond proton. It was found that as the length of the bond of ADP-P (rho) increases, the branches of the adiabatic potential U0(rho) and UN(rho) intersect. At the intersection point, the system can transit to the branch UN(rho), which can lead to a reduction of the barrier and a break of the covalent bond of ADP-P. Presumably, this mechanism is universal for processes of transformation of the chemical energy of ATP to the energy of excited hydrogen bond, a mechanism for the maintenance of heat balance and reduction of entropy in a living organism.