Table 2. Quantification of Biased Agonism (ΔΔlog(τ/K_A)) on GLP-1R^a.

ligand	cAMP:β-arrestin 2	cAMP:calcium mobilization	cAMP:internalization	calcium mobilization:β-arrestin 2	calcium mobilization:internalization	β-arrestin 2:internalization
GLP-1	0.00 ± 0.03	0.00 ± 0.05	0.00 ± 0.05	0.00 ± 0.06	0.00 ± 0.07	0.00 ± 0.05
GLP-1 Val8	0.10 ± 0.05	–0.14 ± 0.05	0.65 ± 0.04****	0.24 ± 0.07	0.79 ± 0.06****	0.55 ± 0.06****

^aΔΔlog(τ/K_A) values determined for GLP-1 and GLP-1 Val8 across different functional outcomes. Data represent the mean ± s.e.m. of 18 independent experiments performed in duplicate for cAMP production and β-arrestin 2 recruitment, 4 independent experiments in duplicate for calcium mobilization, and 6 independent experiments performed in duplicate and triplicate for internalization. Statistical significance was assessed using a repeated measures two-way ANOVA (****P < 0.0001; between GLP-1 and GLP-1 Val8).