Properties of the extracellular calcium binding module of the proteoglycan testican

FEBS Lett. 1997 Sep 15;414(3):557-61. doi: 10.1016/s0014-5793(97)01070-3.

Abstract

The extracellular calcium-binding (EC) module of human testican (115 residues) was obtained in native form by recombinant production in mammalian cell culture and thus shown to represent an independently folding domain. This module showed a large loss in alpha-helix upon calcium depletion. Apparently only one of the two EF hands binds calcium, with a moderate affinity (Kd =68 microM) about 100-fold lower than in the homologous BM-40 protein. No clear evidence was obtained for collagen binding, indicating that EC modules found in different proteins may not share similar functions.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Genetic Vectors / genetics
  • Humans
  • Immune Sera
  • Molecular Sequence Data
  • Osteonectin / chemistry
  • Osteonectin / genetics
  • Osteonectin / metabolism
  • Plasmids / genetics
  • Proteoglycans / chemistry*
  • Proteoglycans / genetics
  • Proteoglycans / metabolism*
  • Rabbits
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Deletion
  • Sequence Homology, Amino Acid
  • X-Ray Diffraction

Substances

  • Immune Sera
  • Osteonectin
  • Proteoglycans
  • Recombinant Proteins
  • Calcium