PhD Scientific Days 2026

Poster Session 3.W - Pharmaceutical Sciences and Health Technologies

Kinetic Characterization of [³H]ASEM Binding at α7 Nicotinic Acetylcholine Receptor

Előadó neve

Dr. Lóska, Dóra

Neptune code

ZAAQQ5

Előadó munkahelye

Department of Pharmacodynamics

Előadó telefonszáma

+36202957541

Előadó e-mail címe

loska.dorka@gmail.com

Az előadás címe

Kinetic Characterization of [³H]ASEM Binding at α7 Nicotinic Acetylcholine Receptor

Szerző(k) neve és munkahelye

Dóra Lóska¹, Ferenc Horti², András Boros³, Tamás Tábi¹, Balázs Lendvai³

1: Department of Pharmacodynamics
2: Gedeon Richter Plc.
3: Gedeon Richter Plc., Semmelweis University Richter Department

Bemutatás módja

Poszter

Szekció

Poster Session 3.W - Pharmaceutical Sciences and Health Technologies

Language of the presentation

Hungarian

Preferred session

Pharmaceutical Sciences and Health Technologies

Összefoglaló szövege

Introduction: The α7 nicotinic acetylcholine receptor (nAChR) is a key pharmacological target in neurological processes. Although positive allosteric modulators (PAMs) have gained increasing attention, their binding characteristics remain incompletely understood. Radioligands are available only for the orthosteric binding site with [11C]ASEM most widely used in human PET studies. Kinetic binding studies are particularly valuable, since they provide mechanistic insight into how fast a ligand binds (kon) and how long it stays bound (koff).
Aims: Our aim was to characterize first the in vitro binding kinetics of [³H]ASEM to human α7 nicotinic acetylcholine receptor and to determine the key kinetic parameters (Kd, koff, kon, t1/2).
Method: Membrane homogenates were prepared from Flp-In 293 cells stably expressing recombinant α7 nACh subunits forming functional homopentameric ion channels. Binding assays were performed at 25 °C using the orthosteric antagonist radioligand [³H]ASEM. Non-specific binding was defined in the presence of 10 µM methyllycaconitine (MLA), and PAMs were applied as pretreatment when required. Association kinetics were assessed over varying incubation times, while dissociation was initiated by excess MLA. Samples were filtered over UniFilter® GF/C, and radioactivity was quantified using a microplate counter.
Results: Kinetic binding analysis of [³H]ASEM at α7 nACh receptors revealed a dissociation rate constant (koff) of 0.462 min⁻¹ and an association rate constant (kon) of 1.0785 nM⁻¹·min⁻¹, corresponding to a dissociation half-life (t1/2) of 1.57 min. These parameters indicate relatively rapid binding kinetics. The equilibrium dissociation constant (Kd) derived from kinetic parameters (koff/kon) was 0.428 nM, while the experimentally determined Kd from equilibrium binding was 0.5654 nM. We began to investigate the effect of a PAM compound (BNC-375) which did not affect the dissociation kinetics of [³H]ASEM.
Conclusion: We determined the kinetic parameters of [³H]ASEM binding at α7 nACh receptor. BNC-375 did not affect [³H]ASEM dissociation kinetics. In addition to the investigation of α7 nACh receptor allosteric modulators, particularly PAMs, which are of significant interest for therapeutic development, we plan to extend these kinetic investigations to agonist radioligand for a more comprehensive assessment of PAMs receptor binding.

University

Semmelweis University

Supervisor

Dr. Tábi Tamás, Dr. Boros András

Publication of my abstract

I give consent to the publication of my abstract on the website of the congress.

phd.section.field

in doctoral studies before complex exam (PhD)

Kind

Szabad

Status

elfogadva

Accepted presentation method

poszter

Előadás fájl jóváhagyás

nem rendelkezett róla

Előadó

8244

Start

14:00

End

14:03