Abstract: | The energy dependence on hydrogen position for a system, consisting of plastoquinone (in different redox states) and histidine molecules was studied. The distance between the atoms forming the hydrogen bond, an oxygen of the quinone molecule and a nitrogen of histidine, was supposed to be fixed. It was shown that for neutral quinone the total energy is minimal when the hydrogen is bound to histidine; for reduced quinone, the probability of hydrogen binding to quinone and histidine is approximately equal (so that a hydrogen bond is formed) and on secondary reduction of plastoquinone, the hydrogen binds to it. |