title: Inactivation of bacterial respiratory chain enzymes by singlet oxygen.
abstract: To distinguish the bactericidal action of singlet oxygen (1O2) from hypohalous acids, wild-type and lycopene transformant E. coli strains were exposed to each of the oxidants and then bacterial viability was investigated. 1O2 was generated by chemical and enzymatic systems at pH 4.5. ExpoSure of wild-type E. coli to 1O2 caused a significant loss of E. coli viability due to inactivation of membrane respiratory chain enzymes by 1O2. This action of 1O2 could be attenuated by lycopene in the bacterial cell membrane. In the lycopene transformant strain of E. coli, inactivation of NADH oxidase and succinate oxidase by hypohalous acids were significantly suppressed, but E. coli viability was unaffected. Based on these findings, we suggest that phagocytic leukocytes produce 1O2 as a major bactericidal oxidant in the phagosome.
authors.affiliation: Shimizu Laboratories, Marine Biotechnology Institute, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tatsuzawa
authors.forename: T
authors.initials: T
authors.lastname: Maruyama
authors.forename: N
authors.initials: N
authors.lastname: Misawa
authors.forename: K
authors.initials: K
authors.lastname: Fujimori
authors.forename: K
authors.initials: K
authors.lastname: Hori
authors.forename: Y
authors.initials: Y
authors.lastname: Sano
authors.forename: Y
authors.initials: Y
authors.lastname: Kambayashi
authors.forename: M
authors.initials: M
authors.lastname: Nakano
mesh_terms: D001965:Bromides / Q000378:metabolism; D002338:Carotenoids / Q000235:genetics / Q000378:metabolism; D004579:Electron Transport; D004794:Enzyme Repression; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D008054:Lipid Peroxides / Q000138:chemical synthesis; D000077276:Lycopene; D009243:NAD / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D009195:Peroxidase / Q000037:antagonists & inhibitors*; D011422:Propionates / Q000138:chemical synthesis; D026082:Singlet Oxygen
chemical_list: C114034:3-(4'-methyl-1'-naphthyl)propionic acid 1',4'-endoperoxide; D001965:Bromides; D008054:Lipid Peroxides; D011422:Propionates; D009243:NAD; D026082:Singlet Oxygen; D002338:Carotenoids; D006861:Hydrogen Peroxide; D009195:Peroxidase; D010100:Oxygen; D000077276:Lycopene