| | 1 | Author
| S. C. Sabat, V. Vijayavergiya, B. C. Tripathy, PrasannaM. Ohanty | Requires cookie* | | | Title
| Inhibitory Effect of Crown Compound on Photoelectron Transport Activity of Beet Spinach Thylakoid Membranes  | | | | Abstract
| The effect o f K-picrate-18-crown-6 (crown) on the photoelectron transport activity o f beet spinach thylakoid membranes was investigated. A ddition o f micromolar concentration o f crown to thylakoid preparation inhibited p-benzoquinone, chloride-indophenol, methyl violo-gen supported Hill activities maximally by 75 per cent in a concentration dependent manner. However, the photosystem I catalyzed reaction remained insensitive to crown suggesting that crown specifically inhibits photosystem II electron transport. Addition o f exogenous electron donors like hydroxylamine or diphenylcarbazide failed to restore the crown induced inhibition o f photosystem II electron transport and lowering o f steady state chlorophyll a fluorescence yield. These observations suggest that crown also inhibits photosystem II catalyzed electron transport after the donation sites o f these exogenous donors. Washing o f the crown pre-treat-ed thylakoids with isolation buffer, relieved the crown inhibited electron transport activity, indicating that this inhibition is reversible. Furthermore, in hydroxylamine washed thylakoids which are devoid o f 0 2 evolution capacity, the hydroxylamine induced increase in chlorophyll a fluorescence o f variable yield was quenched by the addition o f crown. These observations suggest that crown affects the oxygen evolution and inhibits at a site close to photosystem II reaction centres. | | | |
Reference
| Z. Naturforsch. 46c, 87 (1991); received August 14 1990 | | | |
Published
| 1991 | | | |
Keywords
| Crown-Ether, Electron Transport, Photosystem II, Thylakoids, Beet Spinach ( Beta vulgaris) | | | |
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| default:Reihe_C/46/ZNC-1991-46c-0087.pdf | | | | Identifier
| ZNC-1991-46c-0087 | | | | Volume
| 46 | |
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