Abstract
The presence of 1.0 mol/L glycinebetaine during isolation of D1/D2/Cytb559 reaction centre (RC) complexes from photosystem II (PSII) membrane fragments preserved the photochemical activity, monitored as the light-induced reduction of pheophytin and electron transport from diphenylcarbazide to 2.6-dichlorophenol-indophenol.-Glycinebetaine also protected the D1/D2/Cytb559 complexes against strong light-induced damage to the photochemical reactions and the irreversible bleaching of beta-carotene and chlorophyll. The presence of glycinebetaine also enhanced thermotolerance of the D1/D2/Cytb559 complexes isolated in the presence of 1.0 mol/L betaine with an increase in the temperature for 50% inactivation from 29 degrees C to 35 degrees C. The results indicate an increased supramolecular structural stability in the presence of glycinebetaine.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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2,6-Dichloroindophenol / metabolism
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Betaine / pharmacology*
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Chlorophyll / metabolism
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Cytochrome b Group / drug effects
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Cytochrome b Group / metabolism*
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Cytochrome b Group / radiation effects
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Diphenylcarbazide / metabolism
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Electron Transport
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Hot Temperature
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Light-Harvesting Protein Complexes
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Oxidation-Reduction
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Pheophytins / metabolism
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Photobleaching
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Photochemistry
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Photosynthetic Reaction Center Complex Proteins / antagonists & inhibitors
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Photosynthetic Reaction Center Complex Proteins / drug effects
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Photosynthetic Reaction Center Complex Proteins / metabolism*
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Photosynthetic Reaction Center Complex Proteins / radiation effects
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Photosystem II Protein Complex*
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Quinones / metabolism
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Spinacia oleracea / drug effects
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Spinacia oleracea / metabolism
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Spinacia oleracea / radiation effects
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beta Carotene / metabolism
Substances
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Cytochrome b Group
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Light-Harvesting Protein Complexes
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Pheophytins
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Photosynthetic Reaction Center Complex Proteins
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Photosystem II Protein Complex
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Quinones
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beta Carotene
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Chlorophyll
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Diphenylcarbazide
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Betaine
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cytochrome b559
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2,6-Dichloroindophenol