Directed evolution to probe protein allostery and integrin I domains of 200,000-fold higher affinity Academic Article uri icon


MeSH Major

  • Integrins
  • Intercellular Adhesion Molecule-1
  • Proteins


  • Understanding allostery may serve to both elucidate mechanisms of protein regulation and provide a basis for engineering active mutants. Herein we describe directed evolution applied to the integrin alpha(L) inserted domain for studying allostery by using a yeast surface display system. Many hot spots for activation are identified, and some single mutants exhibit remarkable increases of 10,000-fold in affinity for a physiological ligand, intercellular adhesion molecule-1. The location of activating mutations traces out an allosteric interface in the interior of the inserted domain that connects the ligand binding site to the alpha7-helix, which communicates allostery to neighboring domains in intact integrins. The combination of two activating mutations (F265S/F292G) leads to an increase of 200,000-fold in affinity to intercellular adhesion molecule-1. The F265S/F292G mutant is potent in antagonizing lymphocyte function-associated antigen 1-dependent lymphocyte adhesion, aggregation, and transmigration.

publication date

  • April 11, 2006



  • Academic Article



  • eng

PubMed Central ID

  • PMC1458646

Digital Object Identifier (DOI)

  • 10.1073/pnas.0601164103

PubMed ID

  • 16595626

Additional Document Info

start page

  • 5758

end page

  • 63


  • 103


  • 15