Table 4

Properties of mutant NMDA receptors

Subunit Combination	N¹-DnsSpm IC₅₀	n_H	Mutant/wild-type^4-a	No. of oocytes
	μm
NR1/NR2A series
Wild-type NR1/NR2A	0.38 ± 0.11	0.9 ± 0.1		9
NR1(N616Q)/NR2A	5.7 ± 0.8^4-b	0.7 ± 0.1	15	6
NR1(N616R)/NR2A	79 ± 8.2^4-b	1.0 ± 0.1	208	6
NR1(N616G)/NR2A	0.01 ± 0.001^4-b	0.9 ± 0.1	0.03	6
NR1/NR2A(N614Q)	0.09 ± 0.03^4-b	1.1 ± 0.1	0.23	5
NR1/NR2A(N615Q)	1.2 ± 0.2^4-b	0.9 ± 0.1	3	5
NR1/NR2A(N615G)	0.02 ± 0.002^4-b	0.8 ± 0.1	0.05	4
NR1(N616Q)/NR2A(N615Q)	0.19 ± 0.03^4-c	0.8 ± 0.1	0.5	5
NR1(N616Q)/NR2A(N615G)	0.01 ± 0.001^4-b ^, ^4-c	1.0 ± 0.1	0.03	5
NR1/NR2B series
Wild-type NR1/NR2B	0.40 ± 0.07	1.3 ± 0.1		5
NR1(N616Q)/NR2B	5.7 ± 1.2^4-b	0.6 ± 0.1	14	6
NR1/NR2B(N615Q)	0.14 ± 0.02	1.1 ± 0.1	0.35	5
NR1/NR2B(N616Q)	3.2 ± 1.6^4-b	1.1 ± 0.1	8	6
NR1(N616Q)/NR2B(N615Q)	0.07 ± 0.01^4-b ^, ^4-c	1.0 ± 0.1	0.2	5
NR1(N616Q)/NR2B(N616Q)	0.25 ± 0.03^4-c	0.9 ± 0.1	0.6	5

Values for the IC₅₀ and Hill slope (n_H ) of inhibition by N¹-DnsSpm were determined from concentration-inhibition curves using oocytes expressing NR1/NR2 receptors and voltage-clamped at −70 mV. Values are mean ± standard error.

↵4-a Ratio of the IC₅₀ values for N¹-DnsSpm at mutant/wild-type receptors.
↵4-b p < 0.01 compared with wild-type NR1/NR2;
↵4-c p < 0.01 compared with NR1(N616Q)/NR2 (one-way ANOVA with post hoc Tukey’s test, using log IC₅₀ values).