Glutathione peroxidase-like activity of caeruloplasmin as an important lung antioxidant.
The copper-containing plasma protein caeruloplasmin (Cp) has been shown to possess several oxidase activities, but with the exception of its ferrous ion oxidising (ferroxidase) activity which so far appear to be of minor biological relevance. Recently, Kim and colleagues (Kim et al. (1998) FEBS Lett. 431, pp. 473-475) observed that Cp can catalytically remove hydrogen peroxide in the presence of thiols. Here, we show that Cp can remove both hydrogen peroxide and lipid hydroperoxides at physiologically relevant concentrations of reduced glutathione known to be present in lung and lung lining fluid. The glutathione peroxidase-like activity of Cp together with its ferroxidase activity would completely remove the primary reactants required for both Fenton chemistry and lipid peroxidation.
Park
Y S
YS
Department of Biochemistry, Osaka University Medical School, Japan.
Suzuki
K
K
Taniguchi
N
N
Gutteridge
J M
JM
D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D002570:Ceruloplasmin / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D005110:Extracellular Space / Q000201:enzymology; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D008054:Lipid Peroxides / Q000378:metabolism; D008168:Lung / Q000201:enzymology* / Q000378:metabolism; D008956:Models, Chemical; D013438:Sulfhydryl Compounds / Q000378:metabolism
D000975:Antioxidants; D008054:Lipid Peroxides; D013438:Sulfhydryl Compounds; D006861:Hydrogen Peroxide; D005979:Glutathione Peroxidase; D002570:Ceruloplasmin; D005978:Glutathione