Figure 1.

In vitro activity profile of KGNOP1 to the human opioid receptors. (A) Binding curves of KGNOP1 to the human opioid receptors determined in competitive radioligand binding assays. Concentration-dependent inhibition by KGNOP1 of [³H]DAMGO (MOR), [³H]diprenorphine (DOR), [³H]U69,593 (KOR), and [³H]Nociceptin (NOP receptor) binding to membranes of CHO cells stably expressing the human opioid receptors (CHO-hOR). (B) Concentration-dependent stimulation of [³⁵S]GTPγS binding by KGNOP1 in the [³⁵S]GTPγS binding assays using CHO cell membranes stably expressing the human opioid receptors. Data are presented as percentage stimulation relative to the maximum effect of reference full agonists DAMGO (MOR), DPDPE (DOR), U69,593 (KOR), and nociceptin (NOP receptor) (as 100%). Values are expressed as the mean ± SEM (n = 3–4 independent experiments performed in duplicate).