The effect of a full agonist
is greater than that of a partial agonist
because the full agonist
has better (not necessarily more) connections.
For example, in using the "tickle" analogy
, a full agonist
is not just "tickling" the receptor, it is tickling the receptor in the right spot...making the receptor laugh.
Compare this to a partial agonist
where although the partial agonist
is tickling (making connections) just as the full agonist
, the partial agonist
is not making the receptor laugh...and therefore not tickling in the right spot.
When the full agonist
binds, it is able to stabilize the receptor in the active conformation because it has high intrinsic efficacy...it does everything right in the binding site. Everything is in the RaD form.
With the partial agonist
, it doesn't stabilize because it has low intrinsic efficacy. You end up getting a mixture of RaD and RiD, so you get less of an effect.
- Which ligand stabilizes it in the RiD form?
- The inverse agonist (takes it to the left for RiD) while the full agonist takes it to the right (RaD).