title: Glycinebetaine protects the D1/D2/Cytb559 complex of photosystem II against photo-induced and heat-induced inactivation.
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.
authors.affiliation: Department of Regulation Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan.
authors.forename: Suleyman I
authors.initials: SI
authors.lastname: Allakhverdiev
authors.forename: Hidenori
authors.initials: H
authors.lastname: Hayashi
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nishiyama
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Ivanov
authors.forename: Jalal A
authors.initials: JA
authors.lastname: Aliev
authors.forename: Vyacheslav V
authors.initials: VV
authors.lastname: Klimov
authors.forename: Norio
authors.initials: N
authors.lastname: Murata
authors.forename: Robert
authors.initials: R
authors.lastname: Carpentier
mesh_terms: D015086:2,6-Dichloroindophenol / Q000378:metabolism; D001622:Betaine / Q000494:pharmacology*; D002734:Chlorophyll / Q000378:metabolism; D003573:Cytochrome b Group / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D004160:Diphenylcarbazide / Q000378:metabolism; D004579:Electron Transport; D006358:Hot Temperature; D045342:Light-Harvesting Protein Complexes; D010084:Oxidation-Reduction; D010674:Pheophytins / Q000378:metabolism; D038761:Photobleaching; D010777:Photochemistry; D045322:Photosynthetic Reaction Center Complex Proteins / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D045332:Photosystem II Protein Complex; D011809:Quinones / Q000378:metabolism; D018724:Spinacia oleracea / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D019207:beta Carotene / Q000378:metabolism
chemical_list: D003573:Cytochrome b Group; D045342:Light-Harvesting Protein Complexes; D010674:Pheophytins; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D011809:Quinones; D019207:beta Carotene; D002734:Chlorophyll; D004160:Diphenylcarbazide; D001622:Betaine; C019313:cytochrome b559; D015086:2,6-Dichloroindophenol