Figure 6.
Characterization of ICAM-1–binding inhibitory compounds. A, Chemical structures. B, Concentration-dependent inhibition using bead-immobilized COS7-expressed Duffy-binding-like (DBL) 2PF11_0521 domain. Error bars are standard deviations. C, Blocking (black) and reversal (gray) of ICAM-1 binding by compound 5306995, using bead-immobilized Escherichia coli–expressed DBL2PF11_0521 domain. Error bars are standard deviations. D, Both compounds bind to domain, with compound 5306995 having a higher affinity. Compounds at various concentrations were incubated with bead-immobilized DBL2PF11_0521 domain (E. coli expressed and refolded), and unbound compound was removed by washing. Beads were further incubated with ICAM-1 and washed, and binding of ICAM-1 was measured as described in Materials and Methods. Black bars, DBL2PF11_0521 domain; white bars, control protein AMA1 expressed in E. coli. Error bars are standard deviations. Abbreviations: Conc, concentration; IC50, median inhibitory concentration.