The binding of integrin α L β 2 to its ligand intercellular adhesion molecule-1 is required for
immune responses and leukocyte trafficking. Small molecule antagonists of α L β 2 are
under intense investigation as potential anti-inflammatory drugs. We describe for the first
time a small molecule integrin agonist. A previously described α/β I allosteric inhibitor,
compound 4, functions as an agonist of α L β 2 in Ca 2+ and Mg 2+ and as an antagonist in
Mn 2+. We have characterized the mechanism of activation and its competitive and …