TABLE 2

Agonist coupling efficiency parameters for M₁ mAChR-mediated Ca²⁺ elevation in U2OS cells

Data represent the mean ± S.E.M. of four to eight experiments performed in duplicate. The logarithm of the relative coupling efficiency parameter, τ, was determined via nonlinear regression of the data to an operational model of agonism and corrected for receptor expression levels to yield a corrected τ_c parameter (Logτ_c). Antilogarithm shown in parentheses.

Ligand	Logτ_c
Ligand	Wild Type (0.5 pfu/ml)	F⁷⁷I (1.25 pfu/ml)	W¹⁰¹A (0.5 pfu/ml)	Y³⁸¹A (0.5 pfu/ml)
Acetylcholine	2.82 ± 0.07	2.83 ± 0.08	2.83 ± 0.07	2.23 ± 0.07^*
	(661)	(676)	(676)	(169)
Pilocarpine	0.70 ± 0.06	0.44 ± 0.06	0.91 ± 0.07	−2.73 ± 0.94^*
	(5)	(2.8)	(8.1)	(0.002)
AC-42	0.01 ± 0.05	−1.85 ± 0.58^*	1.26 ± 0.06^*	−0.77 ± 0.09
	(1)	(0.014)	(18.2)	(0.17)
77-LH-28-1	0.62 ± 0.06	−0.69 ± 0.11^*	0.33 ± 0.06	−0.85 ± 0.10^*
	(4.2)	(0.20)	(2.13)	(0.14)

↵* Significantly different (p < 0.05) from the wild-type receptor as determined by one- way ANOVA followed by Dunnett's post test.