TABLE 5

Differential modulation of agonist peptides at human GLP-1R 149 or 333 mutants by compound 2 in cAMP accumulation

Data were analyzed using a three-parameter logistic equation as defined in eq. 1. pEC50 values represent the negative logarithm of the concentration of agonist that produces half the maximal response. All data are normalized to the response elicited by 100 μM forskolin and then normalized to the response elicited by 1 μM peptide [GLP-1(1–36)NH2, oxyntomodulin] or 100 nM peptide [GLP-1(7–36)NH2, exendin-4] at each mutant. Values are expressed as mean ± S.E.M. of four to nine independent experiments, conducted in duplicate.

cAMP Accumulation (pEC50)
GLP-1(1–36)NH2+3 μM Compound 2GLP-1(7–36)NH2+3 μM Compound 2Exendin-4+3 μM Compound 2Oxyntomodulin+3 μM Compound 2
Wild-type7.8 ± 0.17.5 ± 0.410.6 ± 0.110.9 ± 0.511.1 ± 0.110.8 ± 0.89.5 ± 0.110.4 ± 0.8*
M149aNDND7.0 ± 0.29.7 ± 0.8*8.5 ± 0.29.6 ± 0.7*ND7.7 ± 1.5*
A1497.0 ± 0.17.8 ± 0.8*8.7 ± 0.110.5 ± 0.2*9.9 ± 0.110.7 ± 0.4*7.6 ± 0.19.6 ± 0.2*
C1497.2 ± 0.17.1 ± 0.79.3 ± 0.110.2 ± 0.510.6 ± 0.211.0 ± 0.98.0 ± 0.19.5 ± 0.8*
F149ND7.2 ± 1.4ND10.0 ± 0.28.8 ± 0.111.1 ± 0.5*7.3 ± 0.28.5 ± 0.7*
I149NDNDND8.9 ± 0.58.8 ± 0.09.9 ± 0.6*ND7.7 ± 3.1
S1497.4 ± 0.17.4 ± 0.510.4 ± 0.210.9 ± 0.811.0 ± 0.111.3 ± 0.59.0 ± 0.110.0 ± 0.4*
V149ND7.3 ± 1.68.5 ± 0.0ND9.8 ± 0.19.8 ± 0.47.3 ± 0.18.7 ± 0.5*
Y149ND7.4 ± 0.7ND10.0 ± 0.38.7 ± 0.110.8 ± 0.2*ND8.3 ± 0.5
C333aNANANANANANA8.2 ± 0.18.3 ± 0.2
A3337.6 ± 0.17.5 ± 0.810.5 ± 0.210.3 ± 0.511.2 ± 0.111.2 ± 0.59.4 ± 0.19.6 ± 0.4
V3338.0 ± 0.17.8 ± 0.810.6 ± 0.110.7 ± 0.511.1 ± 0.111.6 ± 0.49.5 ± 0.110.0 ± 0.5

  • NA, data not experimentally determined in Koole et al., 2011; ND, data unable to be experimentally defined or with incomplete curves.

  • ↵a Data obtained from Koole et al., 2011. Reported values are normalized to 100 nM forskolin.

  • ↵* Statistically significant at P ≤ 0.05, compared with respective peptide control, paired t test.