Table 2. Binding and Signalling Parameter Estimates for Chimeric Peptides^a.

	Equilibrium binding	cAMP			β-arrestin-2
	pKi (M)	pEC50 (M)	Emax (%)	log τ/KA (M)	pEC50 (M)	Emax (%)	log τ/KA (M)
GLP-1	7.8 ± 0.1	9.5 ± 0.1	100	9.5 ± 0.1	6.2 ± 0.1	102 ± 5	6.2 ± 0.1
Chi1	8.2 ± 0.2	9.5 ± 0.1	100	9.5 ± 0.1	6.4 ± 0.1	102 ± 6	6.4 ± 0.1
Chi2	8.2 ± 0.1*	10.0 ± 0.1*	100	10.0 ± 0.1*	6.9 ± 0.1*	104 ± 6	6.9 ± 0.1*
Chi3	9.4 ± 0.1*	10.0 ± 0.1*	100	10.0 ± 0.1*	6.9 ± 0.2*	93 ± 5*	6.8 ± 0.1*
Ex4-ala2	9.4 ± 0.1*	10.1 ± 0.1*	100	10.1 ± 0.1*	7.1 ± 0.2*	97 ± 5	6.8 ± 0.1*
Ex4	9.7 ± 0.1*	10.2 ± 0.1*	100	10.1 ± 0.1*	6.9 ± 0.1*	77 ± 3*	7.0 ± 0.1*
GLP-1-gly2	7.1 ± 0.1*	8.8 ± 0.1*	100	8.9 ± 0.1*	5.7 ± 0.1*	87 ± 4*	5.7 ± 0.1*

^aMean ± SEM parameter estimates from data shown in Figure 1, n = 5 experimental repeats. Binding experiments were performed in HEK293-SNAP-GLP-1R cells, signaling experiments were performed in CHO-K1-βarr2-EA-GLP-1R cells. Signaling parameter estimates were determined from 3-parameter fitting. E_max values are expressed relative to the global maximum for full agonists in each assay; note that all compounds are full agonists for cAMP in this cell model, so E_max was globally constrained to 100% in that assay. *p < 0.05 versus GLP-1, determined by one-way ANOVA with Dunnett’s test.