Table 3.

αLβ2 containing the mutant open I-domain can be inhibited by mAbs to the β2-I-like domain after DTT treatment

mAb	Epitope	% Inhibition
		Wild-type αLβ2		Open αLβ2
		−DTT	+DTT	−DTT	+DTT
TS1/22	αL I-domain	92  ± 1	92  ± 2	87  ± 7	94  ± 1
TS1/18	β2 I-like domain	89  ± 3	97  ± 0.5	0  ± 0	97  ± 2
YFC51	β2 I-like domain	85  ± 1	88  ± 1	1  ± 1	90  ± 1

Binding to ICAM-1 of wild-type αLβ2 activated with mAb CBR LFA-1/2 or open mutant αLβ2 expressed on K562 cells was determined in presence of mAb as described in Table 2, and % inhibition was determined. The amount of binding was similar to that shown in Fig. 2A and was unaffected by DTT.