title: In vitro carotenogenesis and characterization of the phytoene desaturase reaction in Anacystis.
abstract: An in vitro system for carotenogenesis has been developed from the cyanobacterium Anacystis. Precursor conversion is highly effective and almost no colored intermediates before beta-carotene accumulate. These cell-free reactions have been employed to characterize the phytoene desaturation reaction. Phytoene desaturation is dependent on NAD(P)+ and oxygen but insensitive to inhibitors of plant-type monooxygenases. This result suggests a hydride/proton transfer as mechanism for insertion of a double bond into phytoene. Furthermore, feed-back regulation of phytoene desaturase could be demonstrated for most of the subsequent carotenes.
authors.affiliation: Lehrstuhl für Physiologie und Biochemie der Pflanzen, Universität Konstanz, FRG.
authors.forename: G
authors.initials: G
authors.lastname: Sandmann
authors.forename: S
authors.initials: S
authors.lastname: Kowalczyk
mesh_terms: D002338:Carotenoids / Q000096:biosynthesis / Q000378:metabolism*; D000458:Cyanobacteria / Q000201:enzymology*; D010088:Oxidoreductases / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D002338:Carotenoids; D010088:Oxidoreductases; C022398:phytoene dehydrogenase