https://doi.org/10.1351/goldbook.14126
Extent to which a compound activates a receptor to produce a response in an assay under saturating conditions.
Notes:
- Usually compared to results with the positive and negative assay controls. When the compound produces a maximal signal that is \(\pu{100\%}\) of that of the positive control, it is said to be a full agonist and has high efficacy. When the effect plateaus with increasing concentration to reach an intermediary level of activity, the compound is said to be a partial agonist with lower efficacy.
- Due to the common overexpression of receptors in screening assays, it is not always possible to detect differences in efficacy among full agonists. A more accurate assessment of relative efficacy may require systems with lower receptor expression where it is often found that one agonist may show partial agonist character.
See also: partial agonist