Fig. 3 |. Profiling of C5 guano, C6 guano and μOR using TRUPATH Gαβγ biosensors and β-arrestin-1 and β-arrestin-2 efficacy.
a,b, BRET assays for β-arrestin-2 (a) and β-arrestin-1 (b) recruitment in the presence of 10 μM C5 guano, C6 guano, morphine, fentanyl, buprenorphine, 7-OH and DAMGO (all relative to DAMGO). a, C5 guano and C6 guano showed significantly reduced β-arrestin-2 recruitment compared with DAMGO. Minimum, median and maximum values–C5 guano: 23.9%, 29.0%, 42,5%; C6 guano: 2.7%, 14.6%, 38.4%; morphine: −6.0%, 25.8%, 62.6%; 7-OH:−13.1%, −2.4%, 25.2%; DAMGO: 100%, 100%, 100%; fentanyl: 93.5%, 99.7%, 113.8%. b, Similarly, C5 guano and C6 guano showed significantly reduced β-arrestin-1 recruitment compared with DAMGO. Minimum, median and median values–C5 guano: 17.0%, 26.6%, 29.4%; C6 guano: −7.9%, 4.2%, 4.8%; morphine: 7.2%, 25.6%, 50.2%; 7-OH: −8.0%, −1.4%, 0.3%; DAMGO: 100%, 100%, 100%; fentanyl: 77.4%, 77.4%, 98.4. Data are mean ± s.e.m. (n = three experiments each done in duplicate). Primary statistics for a,b are provided in Supplementary Table 2. c–i, Gα-subtype selectivity using TRUPATH on μOR for DAMGO (c), C5 guano (d), C6 guano (e), buprenorphine (f), fentanyl (g), morphine (h) and 7-OH (i). C6 guano showed distinct potencies and efficacies for all six Gα-protein subtypes (Gi1, Gi2, Gi3, GoA, GoB and Gz) with the lowest efficacy for the Gz subtype. j, Efficacy heat map for opioid peptides, biased agonists, partial agonists, morphine or fentanyl template agonists and bitopic ligands using TRUPATH and β-arrestin-1 and β-arrestin-2 activity. Raw curves and values for all compounds are presented in Extended Data Fig. 6 and Extended Data Tables 2 and 3. Data are mean ± s.e.m. (n = three experiments each done in duplicate).