title: [Mechanism of inhibition by local anesthetics of electron transport at the donor site of the photosystem II].
abstract: The mechanism of inhibition by local anaesthetics of the procaine group of electron transport at the donor site of photosystem II (PS II) from pea chloroplasts was investigated. It was found that besides the inactivation of the O2 release system the anaesthetics used at one order of magnitude lesser concentration exert an uncoupling effect. With a rise in pH the inhibiting activity increases; however, this process is not coupled with the protonophore effect but is due to the generation of a neutral form of the amine. The increment of the inhibiting activity of the anaesthetics in the course of deprotonation seems to be regulated by changes in the coefficient of distribution between the membrane and the aqueous phase. The rate of inactivation of the H2O-dissociating complex increases considerably upon illumination. Electron transport through PS II in anaesthetic-treated chloroplasts in restored by diphenylcarbaside, but not by hydroxylamine. It is concluded that the anaesthetics induce the inhibition by interacting with the electron carrier. The role of the Ca2+--calmodulin-like protein in the functioning of the electron transport chain of PS II is discussed.
authors.forename: B K
authors.initials: BK
authors.lastname: Semin
authors.forename: M N
authors.initials: MN
authors.lastname: Chudinovskikh
authors.forename: I I
authors.initials: II
authors.lastname: Ivanov
mesh_terms: D000779:Anesthetics, Local / Q000494:pharmacology*; D002734:Chlorophyll; D003864:Depression, Chemical; D004579:Electron Transport / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D045342:Light-Harvesting Protein Complexes; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins
chemical_list: D000779:Anesthetics, Local; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D002734:Chlorophyll
vernacular_title: Izuchenie mekhanizma ingibirovaniia lokal'nymi anestetikami transporta élektronov na donornom uchastke fotosistemy II.