This study provides a comprehensive fingerprint of NOP receptor pharmacology at the single-transducer level. The lack of marked G protein bias at the NOP receptor, more pronounced than for the classical opioid receptors, may reflect a combination of intrinsic receptor properties and assay limitations. These findings underscore the need for innovative chemotypes and complementary experimental strategies to fully resolve potential transducer bias at the NOP receptor.
Malfacini et al. (Sun,) studied this question.