Table II.

The effect of CD1d alanine substitutions on NKT TCR binding

	NKT15 K deq	NKT15 contact		Effect on affinity
	μM
WT human CD1d	0.58 ± 0.13	-		-
Arg79Aa	0.35 ± 0.02	Asp94α, Arg95α, Arg103αb	Jα	*
Glu83Aa	>25	Tyr48β, Tyr50β	2β	***
Lys86Aa	2.83 ± 0.13	Tyr48β	2β	**
Met87Aa	7.9 ± 0.32	Tyr50β	2β	***
Val147Aa	3.6 ± 0.17	Ser97α, Leu99α	Jα	**
Gln150A	2.5 ± 0.19	Gly96α, Ser97α, Thr98α, Tyr103β	Jα	**

* represents CD1d alanine substitution with <4-fold reduction in binding to NKT TCR compared to the WT value; ** represents CD1d alanine substitution resulting in a 4–6-fold reduction in binding to NKT TCR compared to the WT value; and *** represents CD1d alanine substitution resulting in a >10-fold reduction in binding to NKT TCR compared to the WT value.

^aConserved between human and mouse CD1d.

^bDenotes contacts that are not maintained in the second NKT TCR–CD1d–α-GalCer complex within the asymmetric unit.