Photooxidation of the cytochrome b-559 in the presence of various substituted 2-anilinothiophenes and of some other compounds, in Chlamydomonas reinhardtii

摘要: Abstract Five substituted 2-anilinothiophenes and two carbonylcyanide-phenylhydrazones were comparatively studied with respect to their capacities for inducing photooxidation of the cytochrome b -559 in chloroplast fragments whole cells Chlamydomonas reinhardtii (wild type P -700-lacking mutant Fl 5). In addition, some other compounds: antimycin A, picric acid, tetraphenylboron NH 4 Cl also tested. Cytochrome photooxidations clearly observed presence 2-(3-chloro-4-trifluoromethyl)anilino-3,5-dinitrothiophene (ANT 2p), 2-(3,4,5-trichloro)anilino-3,5-dinitrothiophene 2s), 2-(4-chloro)anilino-3,5-dinitrothiophene and, greater amplitudes, carbonylcyanide- p -trifluoromethoxyphenylhydrazone m -chlorophenylhydrazone, both fragments. Picric A able induce fragments, but not cells. wild type, highest photoinduced redox changes 1.1 (carbonylcyanide- -trifluoromethoxyphenylhydrazone, -chlorophenylhydrazone) 0.6 2p, ANT 2s) μmol oxidized -559/1 mmol chlorophyll, corresponding 40% 23% which could be induced chemically. All these photooxidations, part was inhibited by 3-(3,4-dichlorophenyl)-1,1-dimethylurea occurred 5, appeared mainly Photosystem II-dependent reactions. But 3-(3,4-dichlorophenyl)-1,1-dimethylureainsensitive I-dependent type. On hand, 2-(4-dimethylamine)-anilino-3,5-dinitrothiophene, 2- N -methyl-(3-chloro-4-trifluoromethyl)anilino3,5-dinitrothiophene did any photooxidation. These results discussed taking consideration nature molecular substitutions various tested substances respective acceleration deactivation reactions water-splitting enzyme system Y photosynthesis had been defined elsewhere Renger (Renger, G. (1972) Biochim. Biophys. Acta 256, 428–439) spinach chloroplasts. Like effect, capacity dependent on acidity group number halogenous substituents aromatic ring molecule. The greatest action towards obtained most active agents: 2p 2s.