title: Photochemical electron transport oin photosynthetic reaction centers from Rhodopseudomonas spheroides. 3. Effects of orthophenanthroline and other chemicals.
abstract: Reaction centers from Rhodopseudomonas spheroides mediate the photochemical oxidation of cytochrome c (cyt c), and show a time-varying fluorescence of P870. Analyses of these effects indicate that the reaction centers contain a primary photochemical electron acceptor capable of holding one electron. Native or added ubiquinone (UQ) can act as a secondary electron acceptor. Orthophenanthroline (o-phen) blocks electron transfer from primary to secondary acceptors, and allows the primary acceptor to be exhibited in the foregoing experiments. Other chelators (with the possible exception of 8-hydroxyquinoline) and dichlorophenyldimethylurea (DCMU) are without apparent effect on reaction centers. o-Phen also inhibits the primary photochemical act in reaction centers; this effect is prevented by the presence of UQ. 2-n-Nonyl-4-hydroxyquinoline-N-oxide (NQNO) inhibits the primary photochemistry in reaction centers but does not affect secondary electron transfer.
mesh_terms: D003864:Depression, Chemical; D004237:Diuron / Q000494:pharmacology; D004579:Electron Transport / Q000187:drug effects*; D005227:Fatty Acids; D007700:Kinetics; D008744:Methylamines; D010087:Oxides; D010618:Phenanthrolines / Q000494:pharmacology*; D010777:Photochemistry; D010788:Photosynthesis; D011804:Quinolines / Q000494:pharmacology; D012242:Rhodobacter sphaeroides / Q000378:metabolism; D012241:Rhodopseudomonas / Q000378:metabolism*; D013501:Surface-Active Agents
chemical_list: D005227:Fatty Acids; D008744:Methylamines; D010087:Oxides; D010618:Phenanthrolines; D011804:Quinolines; D013501:Surface-Active Agents; D004237:Diuron