title: Effect of UV radiation on a thermostable superoxide dismutase purified from a thermophilic bacterium isolated from a sterilization drying oven.
abstract: A thermostable superoxide dismutase from a thermophilic bacterium, called Geobacillus wiegeli (GWE1), isolated from the interior of a sterilization drying oven, was purified by anion-exchange and molecular size-exclusion liquid chromatography. On the basis of SDS-PAGE, the purified enzyme was found to be homogeneous and showed an estimated subunit molecular mass of 23.9 kDa. The holoenzyme is a homotetramer of 97.3 kDa. Superoxide dismutase exhibited maximal activity at pH 8.5 and at temperature around 60 ºC. The enzyme was thermostable maintaining 50% of its activity even after 4.5 hours incubation at 60 ºC and more than 70% of its activity after 30 min at 80 ºC. When the microorganism was irradiated with UVA, an increase in the specific activity of superoxide dismutase was observed which was correlated with decreasing levels of anion superoxide, indicating the direct involvement of this enzyme in the capture of reactive oxygen species. This study reports the effects of UV radiation on a superoxide dismutase from a thermophilic bacterium isolated from an anthropogenic environment.
authors.affiliation: Fundacion Científica y Cultural Biociencia, Jose Domingo Canas 2280, Nunoa, Santiago, Chile.
authors.forename: María T
authors.initials: MT
authors.lastname: Monsalves
authors.forename: Maximiliano J
authors.initials: MJ
authors.lastname: Amenábar
authors.forename: Gabriela P
authors.initials: GP
authors.lastname: Ollivet-Besson
authors.forename: Jenny M
authors.initials: JM
authors.lastname: Blamey
mesh_terms: D001419:Bacteria / Q000201:enzymology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects*; D004795:Enzyme Stability / Q000528:radiation effects; D004864:Equipment and Supplies / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D013242:Sterilization / Q000295:instrumentation; D013482:Superoxide Dismutase / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects*; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D013482:Superoxide Dismutase