Allosteric Modulators
Orthosteric vs Allosteric
- The orthosteric receptor site is where the agonist binds to produce its effect.
- The allosteric receptor site is a site where the agonist does NOT bind.
Postitive vs Negative
- We refer to them as positive modulators, if they potentiate the effect of the receptor.
- We refer to them as negative modulators, if they inhibit the effect of the receptor.
Noncompetitive Antagonism via Negative Allosteric Modulation
- If a drug binds to the allosteric site and produces a conformational change in the receptor that makes it unavailable for the agonist to bind to, a negative allosteric modulator, we can call this a noncompetitive antagonist, as well, because we cannot overcome the effect of the antagonist by increasing the concentration of the agonist.