Antioxidant Enzymes. - Superoxide dismutases (SODs) - Catalases - Peroxiredoxins - Glutathione peroxidases

Transcription

1 Antioxidant Enzymes - Superoxide dismutases (SODs) - Catalases - Peroxiredoxins - Glutathione peroxidases Eva Maria Steiner, Samantha Swenson, Mattias Günther and Xiaoxiao Peng 1

2 Eva Maria Steiner June 6,

3 Superoxide Dismutase (SOD) What s that? SODs involvement in: (Familial) amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease) Down s syndrome and premature aging Human Cu-Zn superoxide dismutase (SOD1); PDB: 2C9U (2006) Eva Maria Steiner June 6,

4 Superoxide Dismutase (SOD) Lou Gehrig's disease Eva Maria Steiner June 6,

5 Cu/Zn SOD Mn SOD Fe SOD Human Sod1 (cytoplasmic) Sod2 (mitochondria) Sod3 (extracellular) S. cerevisiae Sod1 (cytoplasmic) Sod2 (mitochondrial) E. coli SodA (cytoplasmic) SodB (inner membrane) SodC (periplasmic) B. subtilis SodA (cytoplasmic) Adapted from Miller (2012) Eva Maria Steiner June 6,

6 Human SOD Genes Zelko et al. (2002) Eva Maria Steiner June 6,

7 Preliminary SOD Data Eva Maria Steiner June 6,

8 Catalase: Catalyze the decomposition of Hydrogen Peroxide to Water and Oxygen Discovered in 1811 by Louis Jacques Thenard Named in 1900 by Oscar Loew Beef liver catalase crystalized in 1937 Molecular weight (60kDa) in brought the amino acid sequence 3D structure in 1981 Human Erythrocyte Catalase PDB: 1DGF Putnam, C.D. et al J. Mol.Biol. Samantha Swenson June 6,

9 Cofactors: Heme and NADPH or Manganese in some Bacteria NADPH: Not essential for the enzymatic conversion of hydrogen peroxide to oxygen and water, but provides protection of catalase against inactivation by hydrogen peroxide Switala, Jacek and Peter Lewewn Archives of Biochemistry and Biophysics. Kirkman, Henry and Gian Gaetani PNAS. Bernroitner, M. et al Journal of Experimental Botany. Samantha Swenson June 6,

10 Species Genes and Localization: E. coli: Cytosol KatG KatE KatF KatP B. subtilis: Extracellular KatA KatX S. cerevisiae Cytosol CTA1 Peroxisome CTT1 H. sapiens: Peroxisome CAT Uhlich, GA Microbiology. Naclerio, G Applied Environmental Microbiology. Bagyan, I Journal of Bacteriology. Bayliak, M Biochemistry. Samantha Swenson June 6,

11 Diseases of Catalase Mutations & Deficiency: Mutations: Diabetes Mellitus Hypertension Vitiligo Deficiency: Acatalasemia à Oral gangrene à Altered lipid, carbohydrate, homocysteine mebabolism à Increased risk of diabetes mellitus Goth, L. et al Mol. Diagn. Samantha Swenson June 6,

12 Peroxiredoxins Ubiquitous family of antioxidant enzymes controlling peroxide levels and mediating signal transduction. Regulated by changes to phosphorylation, redox and possibly oligomerization states. Prxs are produced at high levels in cells: they are among the ten most abundant proteins in Escherichia coli, the second or third most abundant protein in erythrocytes and compose % of the soluble protein in other mammalian cells. An active-site cysteine (the peroxidatic cysteine) is oxidized to a sulfenic acid by the peroxide substrate. Prxs are divided into three classes; typical 2-cys, atypical 2-cys and 1-cys. The recycling of the sulfenic acid back to a thiol distinguishes the classes. Wood, Schröder, Harris, Poole: Structure, mechanism and regulation of peroxiredoxins. Trends in Biochemical sciences Vol 28, No 1, Jan 2003 Mattias Günther June 6,

13 Peroxiredoxins Peroxiredoxin uses thioredoxin to reduce hydrogen peroxide in the following reactions: Bell, Hardingham: CNS peroxiredoxins and their regulation in health and disease. Antioxidants and Redox signaling, Vol 14, No 8, 2011 Mattias Günther June 6,

14 Peroxiredoxins Mechanism of typical 2-cys peroxiredoxins: -The peroxidatic, catalytic cysteine residue (S c ) reduces peroxide and is converted to cysteine sulfenic acid. -The resolving cysteine (S R ) of another prx forms disulfide bond, eliminating H 2 O -This disulfide bond is in turn reduced by Thioredoxin -Atypical Prxs: Functionally monomeric. Both the peroxidatic systeine and its corresponding resolving cysteine are contained within the same polypeptide. -1-Cys Prxs: do not contain a resolving cysteine. The cysteine sulfenic acid instead presumably reduced by other thiol-containing electron donor (Glutathione, lipoic acid, cyclophilin?) Bell, Hardingham: CNS peroxiredoxins and their regulation in health and disease. Antioxidants and Redox signaling, Vol 14, No 8, 2011 Wood, Schröder, Harris, Poole: Structure, mechanism and regulation of peroxiredoxins. Trends in Biochemical sciences Vol 28, No 1, Jan 2003 Mattias Günther June 6,

15 Peroxiredoxins Subgroups and localisation in mammals Prx I Prx II Prx III Prx IV Prx V Prx VI 2-cys 2-cys 2-cys 2-cys Atypical 2-cys 1-cys Cytosol, nucleus Cytosol, membrane Mitochondria Cytosol, Golgi, secreted Mitochondria, peroxisome, cytosol Cytosol Mattias Günther June 6,

16 Glutathione peroxidases: Remove hydrogen peroxide and lipid hydroperoxide Reaction catalyzed by glutathione peroxidase: Gpx-SeH + H 2 O 2 Gpx-SeOH + H 2 O Gpx-SeOH + GSH GPx-Se-GS + H 2 O GPx-Se-GS + GSH Gpx-SeH + GS-SG Together: Gpx 2GSH + H 2 O 2 GS SG + 2H 2 O GR GS SG + NADPH + H + 2 GSH + NADP + Veal EA, Day AM, Morgan BA. Hydrogen peroxide sensing and signaling. Mol Cell Apr 13;26(1):1-14. Xiaoxiao Peng

17 Enzyme Sep in h? Gpx1 Yes Ubiquitous, cytosol and mitochondria Gpx2 Yes Gastrointestinal, cytosolic Location Function Reference Remove H 2 O 2, lipid hydroperoxides Remove H 2 O 2, lipid hydroperoxides Gpx3 Yes plasma Remove H 2 O 2, lipid hydroperoxides Gpx4 Yes Ubiquitous, cytosol and mitochondria Remove H 2 O 2, lipid hydroperoxides, phospholipid hydroperoxides Gpx5 No Epididymis Protects spermatozoa from oxidative damages Beutler et al, 1975, Blood; Esposito et al, 2000, FRBM Chu et al, 1993, JBC Takahashi et al, 1987, ABB Ursini et al, 1985, BBA; Ari et al, 1999, JBC Chabory et al, 2009, J Clin Invest. Gpx6 Yes olfactory Unknown Gregory et al 2003, Science Gpx7 No ER Unknown Bosello et al, 2013, BBA Xiaoxiao Peng

18 Gpx1 LUKE A. ESPOSITO, et al. Mitochondrial oxidative stress in mice lacking the glutathione peroxidase-1 gene. Free Radical Biology & Medicine, Vol. 28, No. 5, pp , 2000 Xiaoxiao Peng

19 Gpx2 F F Chu, J H Doroshow and R S Esworthy. Expression, characterization, and tissue distribution of a new cellular selenium-dependent glutathione peroxidase, GSHPx-GI The Journal of Biological Chemistry, 268, Xiaoxiao Peng

20 Gpx3 Use t-buooh as substrate Kazuhiko Takahashi et al. Purification and characterization of human plasma glutathione peroxidase: A selenoglycoprotein distinct from the known cellular enzyme. ABB, Volume 256, Issue 2, 1 August 1987, Pages Xiaoxiao Peng

21 Gpx4 Fulvio Ursini, Matilde Maiorino, Carlo Gregolin. The selenoenzyme phospholipid hydroperoxide glutathione peroxidase. BBA, Volume 839, Issue 1, 29 March 1985, Pages Xiaoxiao Peng

22 Gpx5 Chabory E. et al. Epididymis seleno-independent glutathione peroxidase 5 maintains sperm DNA integrity in mice. J Clin Invest Jul;119(7): Xiaoxiao Peng