Competitiveness
Competitiveness
Competitive
- The antagonist and agonist compete for the same binding site
- Reduces the number of free receptor sites for agonist binding
Non-competitive
- The antagonist binds to a separate site on the receptor to the agonist
- Can act to change the shape of the agonist binding site (allosteric modulation) or prevent receptor activation without effect on agonist binding
Reversibility
Reversibility
Reversible
- Antagonist forms only short-lasting combinations with the receptor
Irreversible
- Antagonist form a stable covalent bond with the receptor
Surmountability
Surmountability
Surmountable
- The effect of the antagonist can be overcome by increasing concentrations of the agonist
Insurmountable
- The maximum effect of the agonist is reduced by the antagonist and cannot be overcome by increasing concentrations