A5026174072- Receptor Mechanisms and Signaling
- Neuroscience and Neuropharmacology Research
- Neuropeptides and Animal Physiology
- Lipid Membrane Structure and Behavior
- Monoclonal and Polyclonal Antibodies Research
- Computational Drug Discovery Methods
- Pharmacological Effects and Assays
- Neurotransmitter Receptor Influence on Behavior
- Ion channel regulation and function
- Protein Structure and Dynamics
- Protein Kinase Regulation and GTPase Signaling
- Phosphodiesterase function and regulation
- Nicotinic Acetylcholine Receptors Study
- Cellular transport and secretion
- Cholinesterase and Neurodegenerative Diseases
- Asthma and respiratory diseases
- Pharmacological Receptor Mechanisms and Effects
- Mass Spectrometry Techniques and Applications
- Calcium signaling and nucleotide metabolism
- Synthesis and Biological Evaluation
- Neuroinflammation and Neurodegeneration Mechanisms
- Viral Infectious Diseases and Gene Expression in Insects
Czech Academy of Sciences, Institute of Physiology
2015-2025
Czech Academy of Sciences
2013-2025
Barry University
2024
Scripps Research Institute
2024
Bridge University
2024
University of Florida
2024
Friedrich-Alexander-Universität Erlangen-Nürnberg
2017
University of Minnesota
2014
Czech Academy of Sciences, Institute of Experimental Botany
2014
Abstract Proper determination of agonist efficacy is indispensable in the evaluation selectivity and bias to activation specific signalling pathways. The operational model (OM) pharmacological agonism a useful means for achieving this goal. Allosteric ligands bind receptors at sites that are distinct from those endogenous agonists interact with orthosteric domain on receptor. An allosteric modulator an simultaneously receptor form ternary complex, where affects binding affinity agonist....
Functionally selective ligands stabilize conformations of G protein-coupled receptors (GPCRs) that induce a preference for signaling via subset the intracellular pathways activated by endogenous agonists. The possibility to fine-tune functional activity receptor provides opportunities develop drugs selectively signal associated with therapeutic effect and avoid those causing side effects. Animal studies have indicated displaying selectivity at D2 dopamine (D2R) could be safer more...
Abstract Proper determination of agonist efficacy is essential in the assessment selectivity and signalling bias. Agonist a relative term that dependent on system which it measured, especially being receptor expression level. The operational model (OM) functional agonism useful means for using maximal response to ratio potency its equilibrium dissociation constant (K A ) at active state receptor. However, parameter τ inter-dependent two other parameters OM; agonist’s K highest could be...
Methoctramine (<i>N</i>,<i>N</i>9-bis[6-[[(2-methoxyphenyl)-methyl]hexyl]-1,8-octane] diamine) is an M<sub>2</sub>-selective competitive antagonist of muscarinic acetylcholine receptors and exhibits allosteric properties at high concentrations. To reveal the molecular mechanisms methoctramine binding selectivity we took advantage reciprocal mutations M<sub>2</sub> M<sub>3</sub> in second third extracellular loops that are involved ligands. this end performed measurements kinetics...
Twelve homology models of the human M2 muscarinic receptor using different sets templates have been designed Prime program or modeller and compared to crystallographic structure (PDB:3UON). The best were obtained single template closest published structure, M3 (PDB:4DAJ). Adding more (structurally distant) led worse models. Data document a key role in modeling. differ substantially. quality checks built into programs do not correlate with RMSDs cannot be used select model. Re-docking...
Based on the kinetics of interaction between a receptor and G-protein, myriad possibilities may result. Two extreme cases are represented by: 1/Collision coupling, where an agonist binds to free then agonist-receptor complex "collides" with G-protein. 2/Pre-coupling, stable receptor/G-protein complexes exist in absence agonist. Pre-coupling plays important role signal transduction. Odd-numbered muscarinic acetylcholine receptors preferentially couple Gq/11, while even-numbered prefer...
Abstract Interaction of orthosteric ligands with extracellular domain was described at several aminergic G protein-coupled receptors, including muscarinic acetylcholine receptors. The antagonists quinuclidinyl benzilate (QNB) and N-methylscopolamine (NMS) bind to the binding pocket receptor formed by transmembrane α-helices. We show that high concentrations either QNB or NMS slow down dissociation their radiolabeled species from all five subtypes suggesting allosteric binding. affinity site...
Xanomeline (3-(Hexyloxy)-4-(1-methyl-1,2,5,6-tetrahydropyridin-3-yl)-1,2,5-thiadiazole) is a muscarinic agonist that considered to be functionally selective for the M1/M4 receptor subtypes. Part of xanomeline binding resistant washing. Wash-resistant activates receptors persistently, except M5 subtype. Mutation leucine 6.46 isoleucine at M1 or M4 abolished persistent activation by wash-resistant xanomeline. Reciprocal mutation made it sensitive Lowering membrane cholesterol and mutants wild...
Background and Purpose More than 30% of currently marketed medications act via GPCRs. Thus, GPCRs represent one the most important pharmacotherapeutic targets. In contrast to traditional agonists activating multiple signalling pathways, a single pathway new generation drugs with increased specificity fewer adverse effects. Experimental Approach We have synthesized novel muscarinic ACh receptors tested their binding function (on levels cAMP inositol phosphates) in CHO cells expressing...
Binding of muscarinic ligands, both antagonists and agonists, their effects on the conformation M2 acetylcholine receptor were modeled in silico compared to experimental data. After docking an inactive (3UON, 5ZK3, 5ZKB, or 5ZKB) agonists active (4MQS), 100 ns conventional molecular dynamics (MD) followed by 500 accelerated MD was run. Conventional revealed ligand-specific interactions with receptor. Antagonists stabilized during MD. The complex various attained different conformations...
Muscarinic receptors are known to play important biological roles and drug targets for several human diseases. In a pilot study, novel muscarinic antagonists were synthesized used as chemical probes obtain additional information of the pharmacophore. The design these ligands made use current orthosteric allosteric models drug–receptor interactions together with motifs achieve receptor selectivity. This approach has led discovery non‐competitive that strongly bind at secondary site. These...
The membrane cholesterol was found to bind and modulate the function of several G-protein coupled receptors including muscarinic acetylcholine receptors. We investigated binding 20 steroidal compounds neurosteroids steroid hormones Corticosterone, progesterone some bound with affinity 100 nM or greater. established a structure-activity relationship for steroid-based allosteric modulators Further, we show that corticosterone allosterically functional response at physiologically relevant...
The aim of this study was to develop potent and long-acting antagonists muscarinic ACh receptors. 4-hexyloxy 4-butyloxy derivatives 1-[2-(4-oxidobenzoyloxy)ethyl]-1,2,3,6-tetrahydropyridin-1-ium were synthesized tested for biological activity. Antagonists with long-residence time at receptors are therapeutic targets the treatment several neurological psychiatric human diseases. Their effects allow reduced daily doses adverse effects.
Allosteric ligands bind to receptors at sites that are distinct from those endogenous agonists and orthosteric pharmacological agents interact with. Both an allosteric ligand simultaneously the receptor form a ternary complex, where each influences binding affinity of other receptor, either positively or negatively. modulators intensively studied group because their potentially greater selectivity over ligands, with possibility fine tuning effects neurotransmitters hormones. The unlabelled...
Endogenous neurosteroids and their synthetic analogues-neuroactive steroids-have been found to bind muscarinic acetylcholine receptors allosterically modulate binding function. Using radioligand experiments we investigated mode. We show that neuroactive steroids two sites on receptors. Their affinity for the high-affinity site is about 100 nM. low-affinity 10 µM. The occurs at same as of steroid-based WIN-compounds different from common allosteric alcuronium or gallamine located between...
Many neuromuscular blockers act as negative allosteric modulators of muscarinic acetylcholine receptors by decreasing affinity and potency acetylcholine. The blocker rapacuronium has been shown to have facilitatory effects at leading bronchospasm. We examined the influence on (ACh) binding activation individual subtypes expressed in Chinese hamster ovary cells determine its receptor selectivity. At equilibrium bound all with micromolar (2.7-17 μM) displayed cooperativity both high-...
We mutated key amino acids of the human variant M1 muscarinic receptor that target ligand binding, activation, and receptor-G protein interaction. compared effects these mutations on action two atypical functionally preferring agonists (N-desmethylclozapine xanomeline) classical non-selective orthosteric (carbachol oxotremorine). Mutations D105 in binding site mutation D99 located out decreased affinity all tested was translated as a decrease potency accumulation inositol phosphates...
Agonist efficacy denoting the "strength" of agonist action is a cornerstone in proper assessment selectivity and signalling bias. The simulation models are very accurate but complex hard to fit experimental data. parsimonious operational model agonism (OMA) has become successful determination efficacies ranking them. In 1983, Black Leff introduced slope factor OMA make it more flexible allow for fitting steep as well flat concentration-response curves. First, we performed functional analysis...
Accurate ranking of efficacies and potencies agonists is essential in the discovery new selective agonists. For purpose system-independent agonists, operational model agonism (OMA) has become a standard. Many receptors function as oligomers which makes functional responses more complex, requiring an extension original OMA.