Premium
THE INTERACTION OF HUMAN HAEMOGLOBIN WITH ALLOSTERIC EFFECTORS AS A MODEL FOR DRUG‐RECEPTOR INTERACTIONS
Author(s) -
GOODFORD P.J.,
STLOUIS J.,
WOOTTON R.
Publication year - 1980
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1980.tb10867.x
Subject(s) - allosteric regulation , agonist , chemistry , intrinsic activity , receptor , stereochemistry , affinities , biophysics , second messenger system , partial agonist , adenosine triphosphate , effector , binding site , biochemistry , biology
1 The release of bound oxygen from oxyhaemoglobin by allosteric effectors is considered as a model for those drug‐receptor interactions where the primary response to agonist binding is the release of a second messenger species. 2 A theory of haemoglobin oxygenation, based on the two‐state model of Monod, Wyman & Changeux (1965) is used to predict the relationship between ‘pharmacological’ response and dose of agonist. This relationship is the same as that derived from classical pharmacological occupancy theory. 3 The potency of an agonist is a weighted average of its affinities for the two conformational states of the receptor. 4 The efficacy of an agonist depends not only upon its preferential binding to one of the two conformational states, but also on its ability to alter the functional properties of that state by lowering the affinity of the state for the second messenger. 5 2,3‐Diphosphoglycerate and adenosine triphosphate are approximately equipotent and of similar efficacy, but inositol hexaphosphate is about 500 times more potent and has a higher efficacy.