Table 3.

Levels of expression of the mutant M₁ mAChRs relative to WT in whole cell saturation binding assays and flow cytometric analysis, and equilibrium inhibition binding parameters for [³H]NMS and ACh at the WT and mutant M₁ mAChRs. Values represent the mean ± S.E.M. of four experiments performed in duplicate.

	Receptor expressiona		pKAb	pKIc
	[3H]NMS binding	Flow cytometry
WT			9.63 ± 0.14	5.38 ± 0.03
F772.56I	69.2 ± 7.9*	62.0 ± 5.2*	9.65 ± 0.17	5.41 ± 0.02
Y822.61A	40.0 ± 7.6*	38.9 ± 2.6*	9.28 ± 0.08	5.03 ± 0.05*
Y179ECL2A	57.8 ± 11*	57.4 ± 6.0*	9.57 ± 0.18	5.23 ± 0.04
W4007.35A	22.1 ± 5.6*	27.0 ± 1.9*	9.80 ± 0.17	4.85 ± 0.05*

^aValues represent the percentage of expression relative to the WT receptor expression. Normalised data were not significantly different between estimates of cell surface expression from saturation binding versus flow cytometry of fluorescent antibody labelling of epitope tagged receptors. p > 0.05, unpaired Student’s t-test, degree of freedom 6.

^bNegative logarithm of the [³H]NMS equilibrium dissociation constant.

^cNegative logarithm of ACh equilibrium dissociation constant.

^*Significantly different compared to WT, p < 0.05, one-way ANOVA with Dunnett’s post-hoc test.