title: Interaction of carbonyl cyanide m-chlorophenylhydrazone with the photosystem II acceptor side.
abstract: We show that CCCP, known as an uncoupler of photophosphorylation and an ADRY agent, inhibits FeCy photoreduction and coupled O2 evolution by isolated chloroplasts equally (I50 approximately 2 microM), but is practically without effect on the O2 evolution coupled with SiMo reduction within the 0.2-10 microM concentration range. CCCP has no effect on the nanosecond chlorophyll fluorescence in chloroplasts incubated at low light intensity, but decreases it at high light intensity. The electron transfer from reduced TMPD or duroquinol to methylviologen is resistant to CCCP. The efficiency of the CCCP inhibitory action on the FeCy photoreduction depends on the rate of electron flow, which is controlled by the light intensity. The data obtained show that CCCP is oxidized by the photosystem II donor side and is reduced by QP, competing for electrons with FeCy and the cytochrome blf complex.
authors.affiliation: Department of Cell Physiology and Immunology, Moscow State University, Russian Federation.
authors.forename: V D
authors.initials: VD
authors.lastname: Samuilov
authors.forename: E L
authors.initials: EL
authors.lastname: Barsky
mesh_terms: D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000378:metabolism / Q000494:pharmacology*; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism; D003573:Cytochrome b Group / Q000378:metabolism; D003991:Dibromothymoquinone / Q000494:pharmacology; D004237:Diuron / Q000494:pharmacology; D004579:Electron Transport / Q000187:drug effects; D007887:Fabaceae; D005292:Ferricyanides / Q000378:metabolism; D006912:Hydroxyquinolines / Q000494:pharmacology; D045342:Light-Harvesting Protein Complexes; D008982:Molybdenum / Q000378:metabolism; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism*; D045332:Photosystem II Protein Complex; D010946:Plants, Medicinal; D012825:Silicon / Q000378:metabolism; D017655:Silicon Compounds; D013772:Tetramethylphenylenediamine / Q000378:metabolism; D014301:Trinitrobenzenes / Q000494:pharmacology
chemical_list: D003573:Cytochrome b Group; D005292:Ferricyanides; D006912:Hydroxyquinolines; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D017655:Silicon Compounds; D014301:Trinitrobenzenes; C013250:silicomolybdate; C001333:2-(n-heptyl)-4-hydroxyquinoline N-oxide; D003991:Dibromothymoquinone; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C026642:2-iodo-6-isopropyl-3-methyl-2',4,4'-trinitrodiphenyl ether; D008982:Molybdenum; D004237:Diuron; D013772:Tetramethylphenylenediamine; C028033:potassium ferricyanide; D012825:Silicon