Decorin core protein fragment Leu155-Val260 interacts with TGF-beta but does not compete for decorin binding to type I collagen

Arch Biochem Biophys. 1998 Jul 15;355(2):241-8. doi: 10.1006/abbi.1998.0720.


It has been shown that small proteoglycans containing leucine-rich repeats in their core proteins can form complexes with TGF-beta. Decorin, a ubiquitously found molecule of the extracellular matrix, is the best-studied example. Therefore, binding domains on its core protein were investigated using recombinant decorin fragments generated as fusion proteins in prokaryotes. The peptide Leu155-Val260 immobilized by the polyhistidine tag on a nickel chelate column bound TGF-beta1 and -beta2 almost as effectively as the largest fragment (Asp45-Lys359) studied. Other peptides were less effective. For the two peptides Asp45-Lys359 and Leu155-Val260 dissociation constants in the nanomolar range for high-affinity binding sites were calculated in a solid-phase assay with immobilized TGF-beta2. Peptide Asp45-Lys359 also contained a lower affinity binding site. Domains with lower affinity were also found in peptides Asp45-Leu155 and Arg63-Gly190. Peptide Leu155-Val260 also formed complexes with TGF-beta in the liquid phase as determined by equilibrium gel filtration. Furthermore, F(ab') fragments of polyclonal antibodies against peptide Leu155-Val260 interfered with TGF-beta binding to peptide Asp45-Lys359 in a dose-dependent manner. Peptide Leu155-Val260, however, is only a weak competitor of the binding of wild-type decorin to reconstituted type I collagen fibrils. Therefore, independent binding sites of decorin for TGF-beta and type I collagen should exist. In support of this hypothesis saturable binding of TGF-beta1 and TGF-beta2 to collagen-bound native decorin could be demonstrated. The bound cytokine could be released in a biologically active form by collagenase treatment. Thus, decorin may play a biological role in storing this cytokine temporarily in the extracellular matrix and in thereby modulating an interaction of TGF-beta with its signaling receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Binding, Competitive
  • Chromatography, Gel
  • Collagen / metabolism*
  • Decorin
  • Extracellular Matrix Proteins
  • Humans
  • Immune Sera / pharmacology
  • Immunoglobulin Fab Fragments / metabolism
  • Immunoglobulin Fab Fragments / pharmacology
  • Leucine / metabolism
  • Monocytes
  • Peptide Fragments / immunology
  • Peptide Fragments / metabolism
  • Protein Binding
  • Proteoglycans / genetics
  • Proteoglycans / metabolism*
  • Recombinant Proteins / metabolism
  • Transforming Growth Factor beta / metabolism*
  • Tumor Cells, Cultured
  • Valine / metabolism


  • DCN protein, human
  • Decorin
  • Extracellular Matrix Proteins
  • Immune Sera
  • Immunoglobulin Fab Fragments
  • Peptide Fragments
  • Proteoglycans
  • Recombinant Proteins
  • Transforming Growth Factor beta
  • Collagen
  • Leucine
  • Valine