TABLE 3

Agonist coupling efficiency parameters for M1 mAChR-mediated ERK1/2 phosphorylation in U2OS cells

Data represent the mean ± S.E.M. of three 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 τc parameter (Logτc). Antilogarithm shown in parentheses.

LigandLogτc
Wild Type (0.5 pfu/ml)F77I (1.25 pfu/ml)
Acetylcholine2.52 ± 0.032.57 ± 0.03
(330)(371)
Pilocarpine0.37 ± 0.030.29 ± 0.04
(2.34)(1.94)
AC-420.00 ± 0.03N.D.
(1)
77-LH-28-10.33 ± 0.03−0.27 ± 0.03*
(2.13)(0.54)
  • N.D., not determined.

  • * Significantly different (p < 0.05) from the wild-type receptor as determined by Student's t test.