title: Decorin is a Zn2+ metalloprotein.
abstract: Decorin is ubiquitously distributed in the extracellular matrix of mammals and a member of the proteoglycan family characterized by a core protein dominated by leucine-rich repeat motifs. We show here that decorin extracted from bovine tissues under denaturing conditions or produced in recombinant "native" form by cultured mammalian cells has a high affinity for Zn2+ as demonstrated by equilibrium dialyses. The Zn2+-binding sites are localized to the N-terminal domain of the core protein that contains 4 Cys residues in a spacing reminiscent of a zinc finger. A recombinant 41-amino acid long peptide representing the N-terminal domain of decorin has full Zn2+ binding activity and binds two Zn2+ ions with an average KD of 3 x 10(-7) M. Binding of Zn2+ to this peptide results in a change in secondary structure as shown by circular dichroism spectroscopy. Biglycan, a proteoglycan that is structurally closely related to decorin contains a similar high affinity Zn2+-binding segment, whereas the structurally more distantly related proteoglycans, epiphycan and osteoglycin, do not bind Zn2+ with high affinity.
authors.affiliation: Graduate School of Biomedical Sciences, University of Texas, Houston Health Science Center, Houston, Texas 77030, USA.
authors.forename: V W
authors.initials: VW
authors.lastname: Yang
authors.forename: S R
authors.initials: SR
authors.lastname: LaBrenz
authors.forename: L C
authors.initials: LC
authors.lastname: Rosenberg
authors.forename: D
authors.initials: D
authors.lastname: McQuillan
authors.forename: M
authors.initials: M
authors.lastname: Höök
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D058578:Biglycan; D002417:Cattle; D058575:Decorin; D016326:Extracellular Matrix Proteins; D008667:Metalloproteins / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D011509:Proteoglycans / Q000737:chemistry* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D015032:Zinc / Q000737:chemistry* / Q000378:metabolism
chemical_list: D058578:Biglycan; D058575:Decorin; D016326:Extracellular Matrix Proteins; D008667:Metalloproteins; D011509:Proteoglycans; D011993:Recombinant Fusion Proteins; D015032:Zinc