Binding of mouse and human fibulin-2 to extracellular matrix ligands

J Mol Biol. 1995 Dec 15;254(5):892-9. doi: 10.1006/jmbi.1995.0664.


Recombinant mouse and human fibulin-2 were obtained as disulfide-bonded trimers from transfected kidney cell clones and used in solid phase, biosensor and radioligand binding assays. Strong binding occurred with fibronectin and required calcium. A distinct interaction was also observed with nidogen but this was only partially blocked by EDTA. Distinctly weaker affinities were detected for collagen IV, perlecan and the N-terminal globule of collagen VI alpha 3 chain, while no or only little binding activity could be detected for several other collagen types, laminin-1, BM-40, fibulin-1 and vitronectin. This weaker binding reactions were also dependent on calcium. Surface plasmon resonance assays demonstrated for fibulin-2 binding to nidogen and fibronectin high equilibrium dissociation constants (0.5 to 1 microM) due to a rapid initial dissociation of the complexes. This is apparently followed by a slower stabilizing reaction. The fibulin-2 binding site of nidogen could be localized to its C-terminal globular domain G3, which also possesses a high-affinity binding site for laminin-1. Several tests demonstrated competition between the two ligands, probably due to steric hindrance. Binding of nidogen to immobilized fibulin-2 allowed the formation of ternary complexes with collagen IV, perlecan and fibulin-1, which, as shown previously, bind independently of the G3 domain. This indicated multifunctional binding properties for fibulin-2 and several alternative routes for its integration into basement membranes and other extracellular structures.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Calcium-Binding Proteins / metabolism*
  • Clone Cells
  • Extracellular Matrix / metabolism*
  • Extracellular Matrix Proteins / metabolism*
  • Humans
  • Ligands
  • Mice
  • Molecular Sequence Data
  • Peptide Mapping
  • Protein Binding
  • Recombinant Proteins / metabolism


  • Calcium-Binding Proteins
  • Extracellular Matrix Proteins
  • Ligands
  • Recombinant Proteins
  • fibulin 2