Table 1.

Ligand binding properties of wild-type (WT) hNK₁R and binding pocket point mutants, using [³H]-substance-P as a radioligand

Construct	Kd, nM	Ratio of Kd	pKi (L760735)	Ratio of Ki
WT	2.15 $\pm$ 0.22	1.0	8.08 $\pm$ 0.06	1.0
E193A	3.64 $\pm$ 0.37	1.7*	7.66 $\pm$ 0.05	2.6
Y196A	>10,000	ND	ND	ND
H197A	2.94 $\pm$ 0.38	1.4*	7.76 $\pm$ 0.05	2.1
H265A	5.35 $\pm$ 0.47	2.5	6.59 $\pm$ 0.05	31
Y272A	4.51 $\pm$ 0.55	2.1	7.60 $\pm$ 0.08	3.1

ND, not determined. Ratios of K_d and K_i are for mutants over WT values

^*These differences did not rise to statistical significance judged by one-way ANOVA with Dunnett’s posttest (compared with WT, P < 0.05).