TABLE 1

Functional affinity (pK_B) and cooperativity (logαβ) parameters for NPS R568 determined in Ca²⁺_i mobilization assays using an interaction paradigm

Data are mean ± S.E.M. and 95% confidence interval from the indicated number of independent experiments (n).

	NPS R568
	pK_B (95% CI)	Logαβ (95% CI) (αβ)	n
WT	5.99 ± 0.05 (5.89–6.09)	0.55 ± 0.01 (0.52–0.58) (3.5)	17
F612^1.39A	6.39 ± 0.15 (6.03–6.75)	0.35 ± 0.04^{^a} (0.28–0.43) (2.2)	4
A615^1.42V	6.22 ± 0.13 (5.93–6.49)	0.45 ± 0.04 (0.38–0.53) (2.8)	6
F668^2.56A	<5	ND	4
G670^ECL1A	6.39 ± 0.08 (6.23–6.55)	0.09 ± 0.04^{^a} (−0.07–0.25) (1.2)	4
F684^3.36A	5.28 ± 0.18^{^a} (4.79–5.63)	0.35 ± 0.05^{^a} (0.28–0.51) (2.2)	4
F688^3.40A	5.40 ± 0.16^{^a} (5.00–5.73)	0.52 ± 0.05 (0.44–0.65) (3.3)	5
E767^ECL2A	6.36 ± 0.22 (5.93–6.77)	0.25 ± 0.03^{^a} (0.18–0.33) (1.8)	3
A772^5.39V	6.33 ± 0.08 (6.17–6.48)	0.38 ± 0.02^{^a} (0.35–0.42) (2.4)	4
F775^5.42A	6.11 ± 0.07 (5.95–6.27)	0.39 ± 0.02^{^a} (0.36–0.42) (2.5)	4
L776^5.43A	6.40 ± 0.09 (6.20–6.58)	0.46 ± 0.03 (0.40–0.51) (2.9)	4
V817^6.49A	5.89 ± 0.26 (5.29–6.38)	0.37 ± 0.05^{^a} (0.27–0.50) (2.3)	4
W818^6.50A	5.88 ± 0.05 (5.77–5.98)	0.55 ± 0.01 (0.52–0.58) (3.5)	5
F821^6.53A	7.14 ± 0.18^{^a} (6.80–7.58)	0.18 ± 0.02^{^a} (0.14–0.22) (1.5)	4
Y825^6.57A	6.88 ± 0.11^{^a}^,^{^b} (6.65–7.11)	0.07 ± 0.02^{^a}^,^{^c} (0.04–0.10) (1.2)	4
K831^ECL3A	5.60 ± 0.15 (5.26–5.91)	0.60 ± 0.05 (0.49–0.71) (4.0)	4
V833^ECL3A	6.07 ± 0.11 (5.77–6.33)	0.35 ± 0.02^{^a} (0.31–0.40) (2.2)	4
E837^7.32D	7.13 ± 0.16^{^a} (6.85–7.52)	0.26 ± 0.03^{^a} (0.22–0.32) (1.9)	4
E837^7.32I	<5	ND	7
A840^7.35V	6.31 ± 0.13 (6.05–6.56)	0.33 ± 0.03^{^a} (0.28–0.39) (2.1)	4
I841^7.36A	NA	NA	4
A844^7.39V	6.69 ± 0.09^{^a} (6.49–6.90)	0.05 ± 0.09^{^a} (−0.17–0.26) (1.1)	5
L848^7.43A	6.04 ± 0.13 (5.79–6.28)	0.29 ± 0.02^{^a} (0.25–0.32) (1.9)	4

CI, confidence interval; NA, negligible PAM activity; ND, not determined due to weak cooperativity or low affinity.
↵^a significantly different to WT (P < 0.05, one-way ANOVA with Dunnett’s multiple comparisons post-test).
↵^b pK_B determined in interaction studies between AC265347 and NPS R568 (n = 3).
↵^c pK_B was fixed to 6.88 determined in interaction studies between AC265347 and NPS R568.