Table 2.

PTHR1 β-arrestin-1 and −2 Recruitment and NLuc-PTHR1 Affinity for PTH(1-34) and α/β/γ-Analogues 1 and 2.

	β-arrestin-1 Recruitment				β-arrestin-2 Recruitment				NLuc-PTHR1 Affinity
Peptide	pEC50	EC50 (nM)	EC50 relative	% Max	pEC50	EC50 (nM)	EC50 relative	% Max	pIC50	IC50 (nM)	IC50 relative
PTH(1-34)	8.1 ± 0.1	7.2	1	101 ± 3	8.2 ± 0.1	6.8	1	101 ± 3	7.6 ± 0.1	22	1
1	7.0 ± 0.2	100	14	27 ± 3	7.0 ± 0.4	100	15	21 ± 4	6.9 ± 0.1	130	6
2	6.7 ± 0.3	190	26	39 ± 8	7.0 ± 0.4	110	16	30 ± 8	6.1 ± 0.1	720	33

For β-arrestin-1 recruitment, pEC₅₀, EC₅₀ and maximal response (% Max) values represent the average of ≥4 independent experiments. For β-arrestin-2 recruitment, pEC₅₀, EC₅₀ and % Max are the average of ≥3 independent experiments. pEC₅₀ indicates the negative logarithm of the half-maximal effective concentration (EC₅₀). NLuc-PTHR1 pIC₅₀ and IC₅₀ values are the average of 3 independent experiments. pIC₅₀ indicates the negative logarithm of the half-maximal inhibitory concentration (IC₅₀). EC₅₀ and IC₅₀ relative indicate β-arrestin-1 or −2 recruitment potency or NLuc-PTHR1 affinity normalized to PTH(1-34) by the quotient (α/β/γ-analogue/PTH(1-34)). pEC₅₀, pIC₅₀ and % Max uncertainties are expressed as SEM.