Allosteric Modulators: The New Generation of Receptor Antagonist

Table 1.

Selectivity of Agonists and Allosteric Antagonists for Muscarinic Receptor Subtypes: pK A 1 or pK B 2 values

M1 M2 M3 M4 Range3
1 pK A = - log equilibrium dissociation constants for agonists acetylcholine, oxotremorine, carbachol, pilocarpine, and bethanechol for muscarinic receptor subtypes.
2 pK B = - log equilibrium dissociation constants for antagonists alcuronium, strychnine, brucine, vincamine, and eburnamonine for muscarinic receptor subtypes.
3 Range refers to the multiple maximal difference between the affinities (i.e., K A or K B values) of the ligands for the muscarinic receptor subtypes. Data from (3).
Acetylcholine 4.3 4.3 4.5 4.5 1.6
Oxotremorine 5.5 5 5.3 5.2 3.2
Carbachol 4.5 4.2 4.4 4.3 1.6
Pilocarpine 5.1 4.9 5.1 5.2 2.0
Bethanechol 4 4.1 4.1 4 1.3
Alcuronium 5 6.1 5.8 5.6 12.6
Strychnine 5 4.9 5.7 4.8 7.9
Brucine 5.7 4.6 4 6 100
Vincamine 4.8 5.1 5.7 4.2 31.6
Eburnamonine 5.1 4.2 5.2 4.6 10

This Article

  1. MI August 2004 vol. 4 no. 4 222-229