Figure 6.

Effect of histidine mutations on proton activity. (a) Single His to Ala mutations; (b) single His to Phe mutations; (c) Cys mutation and combined His to Ala mutations. GloSensor-cAMP production was measured in transiently transfected HEK293T cells using the GloSensor cAMP assays. Results were independently normalized (0–100%) for potency comparison and represented means ± SEM from a minimum of 6 independent assays, each in quadruplicate. Curves were analyzed in Prism using the built-in four-parameter logistic function. Pharmacological parameters were reported in Table 5.