Table 1.

Kinetics of interaction of I domains with ICAM-1 in the presence of Mg²⁺

I domain	kon, M−1⋅s−1	koff, s−1	KD*, μM
Open	139,000  ± 8,000	0.0249  ± 0.0026	0.185  ± 0.012
Open + DTT	2,980  ± 440	3.86  ± 0.47	1,230  ± 90
Closed	2,110  ± 400	2.84  ± 0.27	1,760  ± 70
Closed + DTT	3,730  ± 370	3.25  ± 0.27	1,340  ± 100
Wild type	2,950  ± 440	5.55  ± 0.65	1,670  ± 100
Wild type + DTT	3,260  ± 290	4.72  ± 0.39	1,630  ± 190

^*K_D was measured by Scatchard analysis of the amount of binding reached before the dissociation phase. These values are very close to those calculated from the k_on and k_off values shown above.