Table 3.

Comparison of binding kinetics of AL-57 and ICAM-1

I domainkon, M−1·s−1 × 10−3
koff, s−1 × 102
KD, nM
AL-57*ICAM-1 AL-57*ICAM-1 AL-57*ICAM-1
WTND3.1 ± 0.1ND460 ± 36ND1,500,000 ± 200,000
IA16.6 ± 13.6133 ± 105.4 ± 5.243 ± 74,700 ± 3,2003,000 ± 440
HA2.1 ± 0.7115 ± 70.0055 ± 0.00571.4 ± 0.123 ± 16150 ± 16
  • Binding kinetics to the alternative conformations of the αL I domain (IA, L161C/F299C mutant; HA, K287C/K294C mutant) was measured by SPR with a BIAcore instrument in the presence of 1 mM MgCl2.

  • *For binding to the IA I domain, k on and k off were obtained by curve-fitting using a 1:1 binding model. K D was calculated by a Scatchard plot using binding at steady state. For binding to the HA I domain, k on and k off were obtained by using a parallel reactions model plus drift to account for baseline offset, and K D was calculated by k off/k on. Data are means ± SEM of at least three independent experiments. ND, binding not detected.

  • Data are from ref. 31.