UCL logo

UCL Discovery

UCL home » Library Services » Electronic resources » UCL Discovery

MOA-stilbene: A new tool for investigation of the reactions of the chloroplast cytochrome bf complex

Rich, PR; Madgwick, SA; Brown, S; von Jagow, G; Brandt, U; (1992) MOA-stilbene: A new tool for investigation of the reactions of the chloroplast cytochrome bf complex. Photosynthesis Research , 34 (3) pp. 465-477. 10.1007/BF00029819.

Full text not available from this repository.

Abstract

MOA-stilbene is known to be a specific inhibitor of the Qo site of mammalian cytochrome bc1 complex. We show that it also binds to the chloroplast cytochrome bf complex. Binding to the reduced enzyme induces a red-shift of the Soret and visible absorption bands of the haems b. Steady state and single turnover experiments with thylakoid membranes show that MOA-stilbene promotes additional 'oxidant-induced reduction' of the b haems and slows their subsequent dark reoxidation. In single turnover experiments, the associated slow phase of the carotenoid bandshift at 518 nm is only partially decreased in apparent extent and rate. These and other effects are similar to those produced by NQNO, a Qi site effector, and by analogy indicate that MOA-stilbene should also be primarily a Qi-site effector of the cytochrome bf complex. MOA-stilbene has less effect on other parts of the photosynthetic chain. This confers an important advantage on MOA-stilbene in that its effects on the cytochrome bf complex can be studied by using Photosystem II to activate turnover. Myxothiazol displays effects on the cytochrome bf complex which are similar to, but much weaker than, those of MOA-stilbene. A Q cycle-based model of turnover of the cytochrome bf complex is presented, which can account for several unusual features of kinetic behaviour. © 1992 Kluwer Academic Publishers.

Type: Article
Title: MOA-stilbene: A new tool for investigation of the reactions of the chloroplast cytochrome bf complex
DOI: 10.1007/BF00029819
UCL classification: UCL > Provost and Vice Provost Offices
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Structural and Molecular Biology
URI: http://discovery.ucl.ac.uk/id/eprint/10026536
Downloads since deposit
0Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item