title: A new redox-dependent mechanism of MMP-1 activity control comprising reduced low-molecular-weight thiols and oxidizing radicals.
abstract: Matrix metalloproteinases (MMPs), a family of zinc-dependent proteinases, participate in remodeling and degradation of the extracellular matrix proteins. The activity of MMPs is thought to be predominately posttranslationally regulated via proteolytic activation of precursor zymogens or via their naturally occurring endogenous inhibitors. Here, using recombinant MMP-1, we investigated new redox-dependent mechanisms of proteinase activity regulation by low-molecular-weight thiols. We find that glutathione (GSH), cysteine, homocysteine, and N-acetylcysteine at physiological concentrations competitively reduce MMP-1 activity up to 75% with an efficiency of cysteine > or = GSH > homocysteine > N-acetylcysteine. In contrast, S-derivatized thiols completely lack this inhibitory activity. Interestingly, the competitive GSH-mediated inhibition of MMP-1-activity can be fully reversed abrogated by oxidizing radicals like (*)NO(2) or Trolox radicals, here generated by UVA irradiation of nitrite or Trolox, two relevant agents in human skin physiology. This redox-dependent reactivation of the inactive GSH-MMP-1-complex comprises GSH oxidation and is significantly inhibited in the presence of ascorbic acid, an effective (*)NO(2) and Trolox radical scavenger. We here offer a new concept of redox-sensitive control of MMP-1 activity based on the inhibitory effect of reduced thiols and reactivation by a mechanism comprising derivatization or oxidation of the MMP-1-bound inhibitory-acting thiol.
authors.affiliation: Institute of Biomedicine/Biochemistry, Biomedicum Helsinki, University of Helsinki, Haartmaninkatu, Finland.
authors.forename: Sabine
authors.initials: S
authors.lastname: Koch
authors.forename: Christine M
authors.initials: CM
authors.lastname: Volkmar
authors.forename: Victoria
authors.initials: V
authors.lastname: Kolb-Bachofen
authors.forename: Hans-Gert
authors.initials: HG
authors.lastname: Korth
authors.forename: Michael
authors.initials: M
authors.lastname: Kirsch
authors.forename: Anselm H C
authors.initials: AH
authors.lastname: Horn
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sticht
authors.forename: Norbert
authors.initials: N
authors.lastname: Pallua
authors.forename: Christoph V
authors.initials: CV
authors.lastname: Suschek
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D001205:Ascorbic Acid / Q000494:pharmacology; D015153:Blotting, Western; D002384:Catalysis / Q000187:drug effects / Q000528:radiation effects; D002478:Cells, Cultured; D002839:Chromans / Q000737:chemistry / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005453:Fluorescence; D005609:Free Radicals / Q000737:chemistry; D005978:Glutathione / Q000494:pharmacology; D019803:Glutathione Disulfide / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D020781:Matrix Metalloproteinase 1 / Q000235:genetics / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D015394:Molecular Structure; D008970:Molecular Weight; D009573:Nitrites / Q000737:chemistry / Q000494:pharmacology*; D010084:Oxidation-Reduction / Q000187:drug effects; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D013379:Substrate Specificity; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D000975:Antioxidants; D002839:Chromans; D005609:Free Radicals; D061965:Matrix Metalloproteinase Inhibitors; D009573:Nitrites; D010455:Peptides; D011994:Recombinant Proteins; D013438:Sulfhydryl Compounds; D020781:Matrix Metalloproteinase 1; D005978:Glutathione; D001205:Ascorbic Acid; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid; D019803:Glutathione Disulfide