Effect of metal chelators on thermoluminescence peaks of spinach chloroplasts and photosystem II particles: probing the water oxidation cycle with 8-hydroxyquinoline.
Inhibition of photosystem II (PS II) activity by 8-hydroxyquinoline (8-HQ) has been investigated in case of spinach chloroplasts and isolated photosystem II particles using the thermoluminescence technique. In presence of 8-HQ, water to methylviologen (MV) photoreduction in isolated chloroplasts is inhibited while the reduction of dichlorophenol indophenol is inhibited in both chloroplasts as well as in photosystem II particles. The activity can be restored fully by addition of diphenylcarbazide (DPC), suggesting that the donor side of water oxidation complex is affected. The changes in the thermoluminescence peaks indicate that the charge recombination processes involving S2 or S3 states of the Kok's cycle are probably affected by 8-HQ treatment.
Hegde
U
U
Department of Chemistry, University of Poona, Pune.
Padhye
S
S
Banerjee
M
M
Vidyasagar
P B
PB
D002614:Chelating Agents / Q000494:pharmacology*; D002734:Chlorophyll / Q000037:antagonists & inhibitors*; D002736:Chloroplasts / Q000187:drug effects / Q000378:metabolism*; D006912:Hydroxyquinolines / Q000494:pharmacology*; D045342:Light-Harvesting Protein Complexes; D010084:Oxidation-Reduction; D015125:Oxyquinoline / Q000494:pharmacology*; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins / Q000037:antagonists & inhibitors*; D013819:Thermoluminescent Dosimetry; D014867:Water / Q000378:metabolism
D002614:Chelating Agents; D006912:Hydroxyquinolines; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D014867:Water; D002734:Chlorophyll; D015125:Oxyquinoline