title: Posttranslational modification of human glyoxalase 1 indicates redox-dependent regulation.
abstract: BACKGROUND
  Glyoxalase 1 (Glo1) and glyoxalase 2 (Glo2) are ubiquitously expressed cytosolic enzymes that catalyze the conversion of toxic alpha-oxo-aldehydes into the corresponding alpha-hydroxy acids using L-glutathione (GSH) as a cofactor. Human Glo1 exists in various isoforms; however, the nature of its modifications and their distinct functional assignment is mostly unknown.
  
  
  RESULTS
  We characterized native Glo1 purified from human erythrocytes by mass spectrometry. The enzyme was found to undergo four so far unidentified posttranslational modifications: (i) removal of the N-terminal methionine 1, (ii) N-terminal acetylation at alanine 2, (iii) a vicinal disulfide bridge between cysteine residues 19 and 20, and (iv) a mixed disulfide with glutathione on cysteine 139. Glutathionylation of Glo1 was confirmed by immunological methods. Both, N-acetylation and the oxidation state of Cys(19/20), did not impact enzyme activity. In contrast, glutathionylation strongly inhibited Glo1 activity in vitro. The discussed mechanism for enzyme inhibition by glutathionylation was validated by molecular dynamics simulation.
  
  
  CONCLUSIONS
  It is shown for the first time that Glo1 activity directly can be regulated by an oxidative posttranslational modification that was found in the native enzyme, i.e., glutathionylation. Inhibition of Glo1 by chemical reaction with its co-factor and the role of its intramolecular disulfides are expected to be important factors within the context of redox-dependent regulation of glucose metabolism in cells.
authors.affiliation: Faculty of Medicine, Institute of Biochemistry, University of Leipzig, Leipzig, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Birkenmeier
authors.forename: Christin
authors.initials: C
authors.lastname: Stegemann
authors.forename: Ralf
authors.initials: R
authors.lastname: Hoffmann
authors.forename: Robert
authors.initials: R
authors.lastname: Günther
authors.forename: Klaus
authors.initials: K
authors.lastname: Huse
authors.forename: Claudia
authors.initials: C
authors.lastname: Birkemeyer
mesh_terms: D000107:Acetylation; D004220:Disulfides / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D007791:Lactoylglutathione Lyase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013058:Mass Spectrometry; D008715:Methionine / Q000378:metabolism; D010084:Oxidation-Reduction; D011499:Protein Processing, Post-Translational
chemical_list: D004220:Disulfides; D008715:Methionine; D007791:Lactoylglutathione Lyase; D005978:Glutathione
references.citation: Biochemistry. 1998 Jun 16;37(24):8754-63
references.pmid: 9628737
references.citation: Blood. 1966 Feb;27(2):145-66
references.pmid: 5901982
references.citation: Endocr J. 2006 Feb;53(1):21-6
references.pmid: 16543668
references.citation: Biochem J. 1961 Jun;79:475-82
references.pmid: 13694091
references.citation: Electrophoresis. 1999 Dec;20(18):3551-67
references.pmid: 10612281
references.citation: J Biol Chem. 2007 Jun 22;282(25):18427-18436
references.pmid: 17468103
references.citation: Biol Chem. 1997 Aug;378(8):793-802
references.pmid: 9377474
references.citation: Mol Aspects Med. 1993;14(4):287-371
references.pmid: 8277832
references.citation: J Biol Chem. 1993 Jan 25;268(3):2141-8
references.pmid: 8380591
references.citation: J Biol Chem. 1999 Apr 2;274(14):9427-30
references.pmid: 10092623
references.citation: Proc Natl Acad Sci U S A. 2002 Mar 19;99(6):3505-10
references.pmid: 11904414
references.citation: Curr Protein Pept Sci. 2007 Oct;8(5):484-95
references.pmid: 17979763
references.citation: J Clin Endocrinol Metab. 1996 Feb;81(2):488-92
references.pmid: 8636255
references.citation: Neurobiol Aging. 2007 Jul;28(7):1044-50
references.pmid: 16781798
references.citation: Mol Cells. 2008 May 31;25(3):332-46
references.pmid: 18483468
references.citation: Methods Enzymol. 2002;348:157-74
references.pmid: 11885269
references.citation: Biochem J. 1947;41(1):56-62
references.pmid: 16748119
references.citation: Proteomics. 2003 Jul;3(7):1145-53
references.pmid: 12872215
references.citation: J Biol Chem. 1993 Mar 15;268(8):5661-7
references.pmid: 8449929
references.citation: Proteomics. 2003 Jul;3(7):1154-61
references.pmid: 12872216
references.citation: Biochem Pharmacol. 2007 Aug 15;74(4):579-89
references.pmid: 17617381
references.citation: Protein Eng. 2003 Sep;16(9):637-9
references.pmid: 14560048
references.citation: Biochem Pharmacol. 2008 Sep 1;76(5):631-44
references.pmid: 18625205
references.citation: Biochim Biophys Acta. 1985 Jan 18;844(1):50-4
references.pmid: 3967051
references.citation: Met Based Drugs. 2008;2008:260146
references.pmid: 18431449
references.citation: Photosynth Res. 2006 Sep;89(2-3):225-45
references.pmid: 17089213
references.citation: Ann N Y Acad Sci. 2005 Jun;1043:135-45
references.pmid: 16037232
references.citation: J Biol Chem. 2001 Sep 7;276(36):33478-87
references.pmid: 11429404
references.citation: Biochem Soc Trans. 2005 Dec;33(Pt 6):1390-3
references.pmid: 16246126
references.citation: Chem Biol Interact. 2001 Jan 30;130-132(1-3):549-62
references.pmid: 11306074
references.citation: Diabetes Res. 1989 Jul;11(3):125-9
references.pmid: 2627763
references.citation: PLoS One. 2008;3(12):e4015
references.pmid: 19107210
references.citation: Biochemistry. 2007 Jul 3;46(26):7765-80
references.pmid: 17555331
references.citation: J Lipid Res. 2001 Feb;42(2):235-40
references.pmid: 11181753
references.citation: Neurobiol Aging. 2007 Jan;28(1):29-41
references.pmid: 16427160
references.citation: Biochem Soc Trans. 2003 Dec;31(Pt 6):1343-8
references.pmid: 14641060
references.citation: Biochem J. 2007 Oct 1;407(1):121-8
references.pmid: 17576200
references.citation: J Mass Spectrom. 2000 Aug;35(8):990-1002
references.pmid: 10972999
references.citation: PLoS One. 2009 Aug 27;4(8):e6805
references.pmid: 19710909
references.citation: Biochemistry. 1999 Oct 12;38(41):13480-90
references.pmid: 10521255
references.citation: Proc Natl Acad Sci U S A. 2002 Jan 22;99(2):949-54
references.pmid: 11792832
references.citation: Methods Enzymol. 1982;90 Pt E:535-41
references.pmid: 7154966
references.citation: Mol Cell Biochem. 2006 Aug;288(1-2):29-36
references.pmid: 16583141
references.citation: Biochem J. 1999 Dec 15;344 Pt 3:837-44
references.pmid: 10585871
references.citation: J Mass Spectrom. 2002 Jan;37(1):15-30
references.pmid: 11813307
references.citation: J Protein Chem. 2000 Jul;19(5):389-97
references.pmid: 11212839
references.citation: Curr Opin Pharmacol. 2007 Aug;7(4):381-91
references.pmid: 17662654
references.citation: Chem Biol Interact. 1998 Apr 24;111-112:137-51
references.pmid: 9679550
references.citation: Mol Cell Biochem. 2009 May;325(1-2):169-78
references.pmid: 19199007
references.citation: Biochemistry. 1982 Sep 28;21(20):4850-7
references.pmid: 7138835
references.citation: J Biol Chem. 1995 Jun 2;270(22):12957-60
references.pmid: 7768882
references.citation: J Biol Chem. 2007 Mar 23;282(12):8678-94
references.pmid: 17242409
references.citation: J Biol Chem. 2000 Nov 24;275(47):36479-82
references.pmid: 11013267
references.citation: Anticancer Res. 1993 Jan-Feb;13(1):151-5
references.pmid: 8476206
references.citation: J Biochem. 2000 Oct;128(4):647-54
references.pmid: 11011147
references.citation: PLoS One. 2008;3(10):e3508
references.pmid: 18946510
references.citation: EMBO J. 1997 Jun 16;16(12):3386-95
references.pmid: 9218781
references.citation: Biochem J. 1996 Mar 1;314 ( Pt 2):463-7
references.pmid: 8670058