title: Chemiluminescence assay for reactive oxygen species scavenging activities and inhibition on oxidative damage of DNA in Deinococcus radiodurans.
abstract: Free radical scavenging effects of the cellular protein extracts from two strains of Deinococcus radiodurans and Escherichia coli against O2-, H2O2 and *OH were investigated by chemiluminescence (CL) methods. The cellular protein extracts of D. radiodurans R1 and KD8301 showed higher scavenging effects on O2- than that of E. coli. D. radiodurans R1 and KD8301 also strongly scavenged H2O2 with an EC50 (50% effective concentration) of 0.12 and 0.2 mg/mL, respectively, compared to that of E. coli (EC50 = 3.56 mg/mL). The two strains of D. radiodurans were effective in scavenging *OH generated by the Fenton reaction, with EC50 of 0.059 and 0.1 mg/mL, respectively, compared to that of E. coli (EC50 > 1 mg/mL). Results from the chemiluminescence assay of *OH-induced DNA damage and the plasmid pUC18 DNA double-strand break (DSB) model in vitro showed that D. radiodurans had remarkably inhibitory effect on the *OH-induced oxidative damage of DNA. The scavenging effects of D. radiodurans on reactive oxygen species (ROS) played an important role in the response to oxidation stress and preventing against DNA oxidative damage, and may be attributed to intracellular scavenging proteins, including superoxide dismutase (SOD) and catalase.
authors.affiliation: Institute of Nuclear-Agricultural Sciences, Zhejiang University, 310029 Hangzhou, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Tian
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wu
authors.forename: Duohong
authors.initials: D
authors.lastname: Sheng
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zheng
authors.forename: Guanjun
authors.initials: G
authors.lastname: Gao
authors.forename: Yuejin
authors.initials: Y
authors.lastname: Hua
mesh_terms: D002374:Catalase / Q000032:analysis; D004249:DNA Damage; D034301:Deinococcus / Q000737:chemistry*; D004926:Escherichia coli / Q000737:chemistry; D016166:Free Radical Scavengers / Q000032:analysis* / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008163:Luminescent Measurements; D010084:Oxidation-Reduction; D010957:Plasmids / Q000528:radiation effects; D017382:Reactive Oxygen Species / Q000032:analysis* / Q000737:chemistry*; D013482:Superoxide Dismutase / Q000032:analysis; D013997:Time Factors
chemical_list: D016166:Free Radical Scavengers; D005609:Free Radicals; D017382:Reactive Oxygen Species; D006861:Hydrogen Peroxide; D002374:Catalase; D013482:Superoxide Dismutase