Serum albumin: Search for new sites of interaction with organophosphorus compounds by the example of soman

Albumin is known to be able to interact with organophosphorus compounds (OPCs), but neither amino acid residues of albumin that are responsible for this interaction nor the nature of the forming bonds have been finally established. Catalytic and pseudocatalytic functions of albumin are under consideration. Possible sites of interaction of albumin with soman have been elucidated by the methods of molecular modeling. Structures of the soman-albumin complexes have been determined by molecular docking. Stability of the obtained complexes has been evaluated by the method of molecular dynamics. The chemical bond between soman and the tyrosine-411 residue has been found to form only after deprotonation of the latter. The tyrosine-150 residue of albumin binds soman more effectively than tyrosine-411, and the tyrosine-150-deprotonation does not determine the efficacy of the binding (sorption) of soman, but affects the stability of the formed bound. It was proposed that the albumin residues of tyrosine-150 and serine-193 could serve as sites of the catalytic interaction with soman. We hypothesized that the deprotonation of an amino acid residue in one albumin site influenced initiation of the ligand binding in the other albumin site (allosteric albumin regulation).