Beta 1 integrin subunit dimerization via disulfide bonds

Biochem Mol Biol Int. 1996 Sep;40(1):53-60. doi: 10.1080/15216549600201522.

Abstract

Integrins of the beta 1 family were isolated from human smooth muscle. SDS-PAGE analysis and subsequent immunoblotting demonstrated that integrin samples contain a protein immunologically related to beta 1 integrin subunit with the previously undescribed apparent molecular mass 205 kD. One-dimensional peptide mapping showed that the 205 kD protein is not a novel beta 1 related integrin subunit, but a beta 1 integrin subunit dimer. After reduction the major part of the beta 1 immunoreactive material migrated from the 205 kD to 130 kD region, indicating that beta 1 integrin subunit dimers were formed via disulfide bonds. When electrophoretically pure beta 1 monomer and dimer forms were analized it was found that during SDS-PAGE about 30% of beta 1 integrin subunit monomers were organized into dimers while approximately 70% of the beta 1 dimer form was partly disrupted into monomers. It was suggested that this steady-state process is a result of a reversible reaction between intra- and intermolecular disulfide bonds. Possible in vivo dimerization of integrins via disulfide bonds is discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, Affinity
  • Disulfides / metabolism*
  • Electrophoresis, Polyacrylamide Gel
  • Humans
  • Integrin beta1 / chemistry*
  • Integrin beta1 / metabolism
  • Molecular Weight
  • Muscle, Smooth / chemistry
  • Protein Conformation

Substances

  • Disulfides
  • Integrin beta1