title: Role of cloned carotenoid genes expressed in Escherichia coli in protecting against inactivation by near-UV light and specific phototoxic molecules.
abstract: Genes controlling carotenoid synthesis were cloned from Erwinia herbicola and expressed in an Escherichia coli strain. Carotenoids protect against high fluences of near-UV (NUV; 320 to 400 nm) but not against far-UV (200-300 nm). Protection of E. coli cells was not observed following treatment with either psoralen or 8-methoxypsoralen plus NUV. However, significant protection of cells producing carotenoids was observed with three photosensitizing molecules activated by NUV (alpha-terthienyl, harmine, and phenylheptatriyne) which are thought to have the membrane as an important lethal target. Protection of carotenoid-producing cells against inactivation was not observed with acridine orange plus visible light but was seen with toluidine blue O plus visible light.
mesh_terms: D000165:Acridine Orange; D000480:Alkynes; D002338:Carotenoids / Q000502:physiology*; D003001:Cloning, Molecular; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000528:radiation effects; D011564:Furocoumarins; D006247:Harmine; D008730:Methoxsalen; D010777:Photochemistry; D011837:Radiation-Protective Agents; D013876:Thiophenes; D014048:Tolonium Chloride; D014466:Ultraviolet Rays
chemical_list: D000480:Alkynes; D011564:Furocoumarins; D011837:Radiation-Protective Agents; D013876:Thiophenes; C019101:alpha-terthienyl; D014048:Tolonium Chloride; D002338:Carotenoids; C019518:phenylheptatriyne; D006247:Harmine; D000165:Acridine Orange; D008730:Methoxsalen