Klaus Masson

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6. Hatefi. Y. (1985) Annu. Rev. Hiochem. 54, 10 151069 Weiss, H., Friedrich, T., Hofaus, G. and Preis, 1). (1991) Eur. J. Hiochem. 197.563-576 Walker, J. E. (1992) Q. Rev. Hiophys. 25,253-324 Degli Esposti, M., DeVries, S., Crimi, M., Ghelli, A., Patarnello, T. and Meyer, A. (1993) Biochim. Biophys. Acta 1143,243-271 Crofts, A., Hacker, B., Harquera, H.,(More)
Members of the new chemical class of 7-substituted 6-bromo-benzo[4,5]imidazo[1,2alpha]pyridin-8,9-diones were found to be excellent inhibitors at the Q(B) site of the photosystem II D1 reaction center protein. The best inhibitors with pI(50)-values of >7 are: dimethyl-propyl, 7.05; i-pentyl, 7.36; t. butyl, 7.47; and i-propyl, 7.51. Displacement experiments(More)
2,4,6-Trinitrophenol (picric acid) is an effective inhibitor of photosynthetic electron transport (pI50 value 6.82). By means of artificial donor and acceptor systems its site of inhibition was located at the reducing side of photosystem II. In addition, picric acid also uncouples photophosphorylation but a much higher concentration is required than for(More)
Quinone, Photosynthetic Electron Transport, Inhibitor UHDBT (5-«-undecyl-6-hydroxy-4,7-dioxobenzothiazole) is an efficient inhibitor of photosyn­ thetic electron transport in chloroplasts from spinach (pl50-value = 7.61) and the green alga Chlamydomonas reinhardii. At low concentrations of UHDBT its site of inhibition is located at the reducing side of(More)
Acridones (9-azaanthracen-10-ones), especially halogen-substituted acridone-carboxylic acids are efficient inhibitors of [14C]ADP binding to the bovine mitochondrial ADP/ATP-carrier protein. 7-Iodoacridone-4-carboxylic acid displaces [14C]ADP in a competitive manner, which indicates that both compounds share an identical binding site. Upon ultraviolet(More)
Azido-ioxynil (3.5-diiodo-2-azido-4-hydroxy-benzonitrile) is a potent photosystem II inhibitor (pI50-value 7.38) and as effective as the parent compound ioxynil itself. [125I]azido-ioxynil exhibits specific binding to isolated thylakoids with a binding constant Kb = 7.14. Upon UV-illumination it binds covalently to thylakoids or photosystem II particles. It(More)
A number of 25 nitro-diphenylethers have been synthesized and assayed for their inhibitory activity in N-methylphenazonium-methosulfate mediated cyclic photophosphorylation. Their p/50-values were in the range from 3.5 to 5.3. A QSAR-analysis revealed that the lipophilicity of the nitro-diphenylethers as expressed by Z:t played a major role. In addition,(More)
In the course of the synthesis of gamma-pyrones, well-known inhibitors of photosystem II electron transport, it turned out that the starting material, acyl derivatives of 2,2-dimethyl-1,3-dioxane-5,6-dione (Meldrum's acid) are potent inhibitors of photosystem II electron transport. Thus, in a simple one-step synthesis from commercial available substances,(More)
Acridones (9-azaanthracen-10-ones) were found to be powerful inhibitors of mitochondrial NADH: ubiquinone oxidoreductase. Their inhibitory activity was best if an alkyl or alkyloxy substituent resided in the 4-position. Biological activity reached a maximum at a chain length of 9-10 A. Halogen substitution in position 7, but not in positions 6 and 7,(More)
The orientation o f acridones, xanthones, 1,4-benzoand naphthoquinones within the pho­ tosystem II Qb herbicide-binding niche was studied by means o f mild trypsination and by esti­ mation o f p /50-values in Chlamydomonas reinhardtii D 1 mutants (Val219 > lie, Ala25, > Val, Phe255 > Tyr, Ser264 > Ala, Asn266 > Thr, and Leu275 > Phe). As judged from the(More)