Publications by authors named "Karolina Pajak"

Previously, it was found that 5-(3-chlorophenyl)-4-hexyl-2,4-dihydro-3-1,2,4-triazole-3-thione (TP-315) effectively protects mice from maximal electroshock-induced seizures. The aim of this study was to determine possible interactions between TP-315 and different molecular targets, i.e.

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  • β2-adrenoceptor (β2-AR) interacts with multiple G proteins (Gs and Gi), with phosphorylation by PKA shifting its coupling preference from Gs to Gi.
  • Recent investigations have found that GRK2-mediated phosphorylation enhances Gi coupling, while (R,R')-fenoterol mainly activates Gs signaling.
  • Research identified Tyr-308 as a critical amino acid for Gs-biased signaling in β2-AR, revealing that specific ligand interactions at this site promote Gs coupling, independent of phosphorylation changes.
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  • MNF inhibits growth and promotes apoptosis in HepG2 cancer cells through activation of cannabinoid receptors.
  • AM251, a synthetic CB1R antagonist, blocks MNF's effects but also activates GPR55, a receptor linked to cancer progression.
  • MNF disrupts GPR55 signaling and related cellular processes, suggesting its potential as a therapeutic agent against cancer.
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The β₂-adrenergic receptor (β₂-AR) agonist [(3)H]-(R,R')-methoxyfenoterol was employed as the marker ligand in displacement studies measuring the binding affinities (Ki values) of the stereoisomers of a series of 4'-methoxyfenoterol analogs in which the length of the alkyl substituent at α' position was varied from 0 to 3 carbon atoms. The binding affinities of the compounds were additionally determined using the inverse agonist [(3)H]-CGP-12177 as the marker ligand and the ability of the compounds to stimulate cAMP accumulation, measured as EC₅₀ values, were determined in HEK293 cells expressing the β₂-AR. The data indicate that the highest binding affinities and functional activities were produced by methyl and ethyl substituents at the α' position.

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Lipophilicity is a physicochemical property of crucial importance in medicinal chemistry. On the molecular level it encodes information on the network of inter- and intramolecular forces affecting drug transport through lipid structures as well as drug's interactions with the target protein. In result, on the organism level, lipophilicity is an important factor defining pharmacokinetics and pharmacodynamics of a drug substance.

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G protein-coupled receptors (GPCRs) are integral membrane proteins that change conformation after ligand binding so that they can transduce signals from an extracellular ligand to a variety of intracellular components. The detailed interaction of a molecule with a G protein-coupled receptor is a complicated process that is influenced by the receptor conformation, thermodynamics, and ligand conformation and stereoisomeric configuration. To better understand the molecular interactions of fenoterol analogs with the β(2)-adrenergic receptor, we developed a new agonist radioligand for binding assays.

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