The compact conformation of fibronectin is determined by intramolecular ionic interactions.

Published

Journal Article

Fibronectin exists in a compact or extended conformation, depending upon environmental pH and salt concentration. Using recombinant fragments expressed in bacteria and baculovirus, we determined the domains responsible for producing fibronectin's compact conformation. Our velocity and equilibrium sedimentation data show that FN2-14 (a protein containing FN-III domains 2 through 14) forms dimers in low salt. Experiments with smaller fragments indicates that the compact conformation is produced by binding of FN12-14 of one subunit to FN2-3 of the other subunit in the dimer. The binding is weakened at higher salt concentrations, implying an electrostatic interaction. Furthermore, segment FN7-14+A, which contains the alternatively spliced A domain between FN11 and 12, forms dimers, whereas FN7-14 without A does not. Segment FN12-14+A also forms dimers, but the isolated A domain does not. These data imply an association of domain A with FN12-14, and the presence of A may favor an open conformation by competing with FN2-3 for binding to FN12-14.

Full Text

Duke Authors

Cited Authors

  • Johnson, KJ; Sage, H; Briscoe, G; Erickson, HP

Published Date

  • May 28, 1999

Published In

Volume / Issue

  • 274 / 22

Start / End Page

  • 15473 - 15479

PubMed ID

  • 10336438

Pubmed Central ID

  • 10336438

International Standard Serial Number (ISSN)

  • 0021-9258

Digital Object Identifier (DOI)

  • 10.1074/jbc.274.22.15473

Language

  • eng

Conference Location

  • United States