title: TSG-6 transfers proteins between glycosaminoglycans via a Ser28-mediated covalent catalytic mechanism.
abstract: Studies of the interaction between Bikunin proteins, tumor necrosis factor-stimulated gene-6 protein (TSG-6), and glycosaminoglycans have revealed a unique catalytic activity where TSG-6/heavy chain 2 transfer heavy chain subunits between glycosaminoglycan chains. The activity is mediated by TSG-6/heavy chain 2 and involves a transient SDS stable interaction between TSG-6 and the heavy chain to be transferred. The focus of this study was to characterize the molecular structure of this cross-link to gain further insight into the catalytic mechanism. The result showed that the C-terminal Asp residue of the heavy chains forms an ester bond to Ser(28) beta-carbon of TSG-6 suggesting that this residue plays a role during catalysis.
authors.affiliation: Center for Insoluble Protein Structures (inSPIN) and Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology, University of Aarhus, 8000 Aarhus C, Denmark.
authors.forename: Kristian W
authors.initials: KW
authors.lastname: Sanggaard
authors.forename: Carsten S
authors.initials: CS
authors.lastname: Sonne-Schmidt
authors.forename: Toke P
authors.initials: TP
authors.lastname: Krogager
authors.forename: Torsten
authors.initials: T
authors.lastname: Kristensen
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Wisniewski
authors.forename: Ida B
authors.initials: IB
authors.lastname: Thøgersen
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Enghild
mesh_terms: D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000502:physiology*; D002460:Cell Line; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000494:pharmacology; D006025:Glycosaminoglycans / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry; D012694:Serine / Q000737:chemistry*; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D015815:Cell Adhesion Molecules; D003432:Cross-Linking Reagents; D006025:Glycosaminoglycans; D010455:Peptides; D011994:Recombinant Proteins; C072273:TNFAIP6 protein, human; D012967:Sodium Dodecyl Sulfate; D012694:Serine; D002244:Carbon