The international journal of biochemistry & cell biology
September 1, 2010
Hugo R Arias, Avraham Rosenberg, Katarzyna M Targowska-Duda et al.
29 citations
Ibogaine blocks human alpha3beta4-nicotinic acetylcholine receptors (AChRs) by binding to a site in the receptor's ion channel, with about nine times higher potency than phencyclidine (PCP). Ibogaine binds with relatively high affinity (Kd = 0.46 ± 0.06 μM) to a single site in the channel and dissociates more slowly from the desensitized receptor than from the resting one, which may prolong the desensitized state. PCP inhibits ibogaine binding, indicating overlapping binding sites between the serine and valine/phenylalanine rings. The interaction is mainly via van der Waals contacts, with local conformational changes suggested by entropic contributions. These findings suggest ibogaine's mechanism involves stabilizing the receptor in a shut-down state.
The international journal of biochemistry & cell biology
September 1, 2011
Hugo R Arias, Dominik Feuerbach, Katarzyna M Targowska-Duda et al.
10 citations
Ibogaine analogs inhibit epibatidine-induced calcium influx in human muscle acetylcholine receptors with a potency order: 18-methylaminocoronaridine and 18-methoxycoronaridine are most potent, followed by ibogaine and catharanthine, then albifloranine. The analogs bind more strongly to the TCP binding site when the receptor is in the desensitized state versus the resting state, and they enhance cytisine binding to resting receptors. The affinity of the analogs correlates with their molecular volume, with an optimal volume around 345 cubic angstroms for the ibogaine site, suggesting the size of the binding site between the serine and nonpolar rings is crucial for binding and desensitization.
The international journal of biochemistry & cell biology
November 1, 2024
Jasmine Jade Butler, Daria Ricci, Chloé Aman et al.
8 citations
Classical psychedelics, which bind to serotonin receptors (5-HTRs), have complex and region-specific effects on the activity of monoaminergic neurons. They can inhibit the firing of serotonergic neurons without necessarily reducing serotonin release in all brain regions, and similarly inhibit noradrenergic neuron spontaneous activity without consistently decreasing noradrenaline release. Their influence on dopaminergic systems is also complex, with opposing effects depending on the specific serotonin receptor subtype and the brain state. Overall, there is no single, clear neuronal signature for how psychedelics affect monoamine systems; instead, the effects are state-dependent and region-dependent.