Disulfide-bonding between Drosophila laminin beta and gamma chains is essential for alpha chain to form alpha betagamma trimer

FEBS Lett. 1997 Jul 21;412(1):211-6. doi: 10.1016/s0014-5793(97)00780-1.


Assembly of Drosophila laminin alpha, beta and gamma chains was analyzed by immunoprecipitation of the lysate from metabolically radiolabeled Kc 167 cells with chain-specific antibodies followed by two dimensional electrophoresis in which non-reducing and reducing SDS gel electrophoresis are combined. Precipitation of monomeric beta (or gamma) with anti-gamma (or -beta) antibody revealed that beta and gamma form stable dimer before they are disulfide-bonded to each other. In contrast, alpha associates with neither monomeric beta, monomeric gamma nor betagamma dimer without disulfide-bonding but only with disulfide-bonded betagamma dimer to form alpha betagamma trimers. These results thus demonstrated that the interchain disulfide-boding between beta and gamma is essential for alpha to form alpha betagamma trimer. We also found that the alpha betagamma trimer can be secreted with alpha chain either disulfide-bonded or not bonded to the disulfide-bonded betagamma dimer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Basement Membrane / chemistry
  • Cell Line
  • Dimerization
  • Disulfides / metabolism*
  • Drosophila / chemistry*
  • Electrophoresis, Gel, Two-Dimensional
  • Immunoblotting
  • Immunosorbent Techniques
  • Laminin / chemistry*
  • Laminin / metabolism*
  • Macromolecular Substances
  • Mercaptoethanol / pharmacology


  • Disulfides
  • Laminin
  • Macromolecular Substances
  • Mercaptoethanol