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Studies on the structure of the ligand-īinding site of the brain D1 dopamine receptor. Las variaciones del pH sobre la union de agonistas y antagonistas al Receptor system of human platelets: role for intraplatelet sodium in receptor binding. Receptor binding sites using physico-chemical parameters and modifyingĪgents. Differentiation of pre- and post-synaptic high affinity serotonin Modulation of agonist interactions with -ketanserin-labelled receptors.Ĩ. ConstitutiveĪctivity of receptors coupled to guanine nucleotide regulatory proteins. Induced activated state of the _2-adrenergic receptor. A ternary complex modelĮxplains the agonist-specific binding properties of the adenylate cyclase-Ĭoupled _-adrenergic receptor.
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Efficacy as the molecular property of a ligand. Structure and function of G protein-coupled receptors. Poorly formated references will probably not work.ġ. If it does not appear to be in cogprints you will be forwarded to the paracite service. Select the SEEK icon to attempt to find the referenced article. Sulfhydryl, ligand efficacy, thiol, two-state model, receptor theory, signal activation, molecular model, cysteine Using this approach, we can distinquish between the efficacies of agonists with varying molecular structures and account for the differences between the properties of agonists and antagonists. Therefore, the cysteine makes the largest contribution to ligand efficacy. The difference in interaction energy between the two forms of cysteine makes the largest contribution to this electrostatic interaction energy difference. Molecular modeling of the third transmembrane domain of the 5-HT2A receptor, which contains a conserved cysteine, shows that efficacy is determined by the difference between the electrostatic interaction energies of a ligand with the acid and base forms of the receptor model.
#Activator protein free#
Efficacy may also be described in thermodynamic terms as the coupling free energy involving a ligand and the acid and base states of the receptor. In general, efficacy is determined by the preference of a ligand for the base of the receptor. We have shown that pH-dependent binding of agonists is closely correlated with measurements of ligand efficacy at the 5-HT2A receptor. We have derived a two-state acid-base model for cysteine modulation of ligand binding which leads to a description of ligand efficacy. Since treatment of receptors with reducing agents produces functional activation and potentiates agonist stimulation, it is likely that this free sulfhydryl modulates receptor activation. The increase of the affinity of agonists with an increase in pH and experiments using thiol-specific reagents indicate that G protein-coupled receptors contain an ionizable cysteine residue at the ligand binding site.