Na/K-ATPase Glutathionylation: in silico Modeling of Reaction Mechanisms

Na,K-ATPase is a redox-sensitive transmembrane protein. Understanding the mechanisms of Na,K-ATPase redox regulation can help to prevent impairment of Na,K-ATPase functioning under pathological conditions and reduce damage and death of cells. One of the basic mechanisms to protect Na,K-ATPase against stress oxidation is the glutathionylation reaction that is aimed to reduce several principal oxidized cysteines (244, 458, and 459) that are involved in Na,K-ATPase action regulation. In this study, we carried out in silico modeling to evaluate glutathione affinity on various stages of Na,K-ATPase action cycle, as well as to discover a reaction mechanism of disulfide bond formation between reduced glutathione and oxidized cysteine. To achieve this goal both glutathione and Na,K-ATPase conformer sampling was applied, the reliability of the protein-ligand complexes was examined by MD assay, the reaction mechanism was studied using semi-empirical PM6-D3H4 approach that could have a deal with large organic systems optimization.