title: Production of two different catalase-peroxidases by Deinococcus radiophilus.
abstract: The production of two kinds of catalase-peroxidase, viz. catalase-2 and catalase-3 of Deinococcus radiophilus varied depending upon growth phases and oxidative stress. A gradual increase in total catalase activity occurred during exponential and stationary phase. Electrophoretic resolution of these catalases in Deinococcal cell extracts revealed the uniform occurrence of catalase-2 and the appearance of catalase-3 only during the late exponential and stationary phase. A substantial increase in total catalase was observed in either hydrogen peroxide- or UV-treated cells. Monitoring of D. radiophilus catalase activity in the oxidative stressed and non-treated cells by gel electrophoresis followed by densitometry revealed the several-fold increase in catalase-3, which is above the constant level of catalase-2. The occurrence of catalase-3 and catalase-2 revealed by fractionation of sucrose-shocked cells suggests that catalase-3 is a cytosolic inducible enzyme whereas catalase-2 is the membrane-associated constitutive enzyme.
authors.affiliation: Department of Microbiology, College of Natural Sciences and Research Institute for Genetic Engineering, Chungbuk National University, Cheongju, Chungbuk, South Korea.
authors.forename: E J
authors.initials: EJ
authors.lastname: Yun
authors.forename: Y N
authors.initials: YN
authors.lastname: Lee
mesh_terms: D002374:Catalase / Q000096:biosynthesis*; D002462:Cell Membrane / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D006095:Gram-Positive Cocci / Q000201:enzymology* / Q000254:growth & development / Q000528:radiation effects; D006861:Hydrogen Peroxide / Q000494:pharmacology; D018384:Oxidative Stress; D009195:Peroxidase / Q000096:biosynthesis*; D014466:Ultraviolet Rays
chemical_list: D006861:Hydrogen Peroxide; D002374:Catalase; D009195:Peroxidase