title: Violaxanthin de-epoxidase, the xanthophyll cycle enzyme, requires lipid inverted hexagonal structures for its activity.
abstract: Bilayer-forming lipids were shown to be ineffective in sustaining the enzymatic activity of violaxanthin de-epoxidase. On the other hand, non-bilayer-forming lipids, regardless of their different chemical character, ensured high activity of violaxanthin de-epoxidase, resulting in conversion of violaxanthin to zeaxanthin. Our data indicates that the presence of lipids forming reversed hexagonal structures is necessary for violaxanthin de-epoxidase activity and this activity is dependent on the degree of unsaturation of the fatty acids. The significance of the reversed hexagonal phase domains in the conversion of violaxanthin into zeaxanthin in model systems and in the native thylakoid membranes is discussed.
authors.affiliation: Department of Chemistry, Pedagogical University, ul. Podchorazych 2, 30-084 Kraków, Poland. latowski@interia.pl
authors.forename: Dariusz
authors.initials: D
authors.lastname: Latowski
authors.forename: Hans-Erik
authors.initials: HE
authors.lastname: Akerlund
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Strzałka
mesh_terms: D002855:Chromatography, Thin Layer; D004789:Enzyme Activation; D038983:Galactolipids / Q000737:chemistry; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry*; D031427:Narcissus / Q000201:enzymology; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship; D024341:Xanthophylls / Q000737:chemistry* / Q000378:metabolism; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism
chemical_list: D038983:Galactolipids; D008051:Lipid Bilayers; D008081:Liposomes; D010940:Plant Proteins; D024341:Xanthophylls; C007388:digalactosyldiacylglycerol; C009909:monogalactosyldiacylglycerol; D019207:beta Carotene; C005613:violaxanthin; D010088:Oxidoreductases; C023290:violaxanthin de-epoxidase