Properties of Selenium-Induced Glutathione Peroxidase in Low-CO2-Grown Chlamydomonas reinhardtii

Shigeoka, Shigeru; Takeda, Toru; Hanaoka, Takahito; Yokota, Akiho; Kitaoka, Shôzaburô; Iizuka, Yoshitomi

doi:10.1007/978-94-009-0511-5_766

Cited by 3 publications

(1 citation statement)

References 6 publications

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“…Here we also discuss the physiological function of the enzyme coupled with the redox cycle of glutathione in Chlamydomonas. Part of these results has been published already [17].…”

Section: Introductionmentioning

confidence: 97%

Characterization and immunological properties of selenium-containing glutathione peroxidase induced by selenite in Chlamydomonas reinhardtii

Shigeoka

Takeda

Hanaoka

1991

Biochemical Journal

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The selenite-induced glutathione peroxidase in Chlamydomonas reinhardtii has been purified about 323-fold with a 10% yield, as judged by PAGE. The native enzyme had an Mr of 67,000 and was composed of four identical subunits of Mr 17,000. Glutathione was the only electron donor, giving a specific activity of 193.6 mumol/min per mg of protein. L-Ascorbate, NADH, NADPH, pyrogallol, guaiacol and o-dianisidine did not donate electrons to the enzyme. In addition to H2O2, organic hydroperoxides were reduced by the enzyme. The Km values for glutathione and H2O2 were 3.7 mM and 0.24 mM respectively. The enzyme reaction proceeded by a Ping Pong Bi Bi mechanism. Cyanide and azide had no effect on the activity. The enzyme contained approx. 3.5 atoms of selenium per mol of protein. On immunoprecipitation, Chlamydomonas glutathione peroxidase was precipitated and its activity was inhibited about 90% by the antibody raised against bovine erythrocyte glutathione peroxidase. The antibody also cross-reacted with the subunits of Chlamydomonas glutathione peroxidase in Western blotting SDS/PAGE. In terms of enzymic, physico-chemical and immunological properties, the experimental results demonstrate clearly that Chlamydomonas glutathione peroxidase resembles other well-characterized glutathione peroxidases from animal sources that contain selenium.

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“…Here we also discuss the physiological function of the enzyme coupled with the redox cycle of glutathione in Chlamydomonas. Part of these results has been published already [17].…”

Section: Introductionmentioning

confidence: 97%

Characterization and immunological properties of selenium-containing glutathione peroxidase induced by selenite in Chlamydomonas reinhardtii

Shigeoka

Takeda

Hanaoka

1991

Biochemical Journal

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Metabolic activation of meta-phenylenediamine by the alga Chlamydomonas reinhardtii

Vlček

Miadoková

Vlčková

et al. 1997

Mutation Research/Genetic Toxicology and Environmental Mutagene

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Purification and characterization of glutathione reductase from Chlamydomonas reinhardtii

Takeda¹,

Ishikawa²,

Shigeoka³

et al. 1993

Journal of General Microbiology

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Glutathione reductase was purified to homogeneity from the unicellular alga Chlamydomonas veinhavdtii. The enzyme was a monomer with a motecular mass of 54-56 kDa as judged by gel filtration and SDS-PAGE. The activity was maximal at pH 8.2 and 49The enzyme was specific for NADPH, but not for NADH. The reverse reaction with NAD(P)' and GSH (glutathione, reduced form) was not observed in the pH range 443-8.2. K, values for NADPH and GSSG (glutathione, oxidized form) were 10.6 VM and 54-1 p~, respectively. Thiol inhibitors and metal ions such as Hg2+ and Cu'' markedly inhibited the enzyme activity. Activity was lost when the apoenzyme was prepared by dialysis, but was restored to 40% of the original activity by the addition of 50 ~M -F A D .The enzyme reaction proceeded via a branching mechanism. Upon immunoprecipitation, glutathione reductase activity of C. reirtihardtii was inhibited 50 YO and 90 % by antibodies generated against spinach and Euglena giutathione reductases, respectively. Both antibodies cross-reacted with C. reinhardtii glutathione reductase in an immunoblot analysis.

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Properties of Selenium-Induced Glutathione Peroxidase in Low-CO2-Grown Chlamydomonas reinhardtii

Cited by 3 publications

References 6 publications

Characterization and immunological properties of selenium-containing glutathione peroxidase induced by selenite in Chlamydomonas reinhardtii

Characterization and immunological properties of selenium-containing glutathione peroxidase induced by selenite in Chlamydomonas reinhardtii

Metabolic activation of meta-phenylenediamine by the alga Chlamydomonas reinhardtii

Purification and characterization of glutathione reductase from Chlamydomonas reinhardtii

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