Probing the Histamine H Receptor Binding Site to Explore Ligand Binding Kinetics.

Analysis of structure-kinetic relationships (SKR) can contribute to an improved understanding of receptor-ligand interactions. Here, fragment (4-(2-benzylphenoxy)-1-methylpiperidine) was used in different fragment growing approaches to mimic the putative binding mode of the long residence time (RT) ligands olopatadine, acrivastine, and levocetirizine at the histamine H receptor (HR). SKR analyses reveal that introduction of a carboxylic acid moiety can increase RT at HR up to 11-fold.

The Role of Water Networks in Phosphodiesterase Inhibitor Dissociation and Kinetic Selectivity.

In search of new opportunities to develop Trypanosoma brucei phosphodiesterase B1 (TbrPDEB1) inhibitors that have selectivity over the off-target human PDE4 (hPDE4), different stages of a fragment-growing campaign were studied using a variety of biochemical, structural, thermodynamic, and kinetic binding assays. Remarkable differences in binding kinetics were identified and this kinetic selectivity was explored with computational methods, including molecular dynamics and interaction fingerprint analyses. These studies indicate that a key hydrogen bond between Gln and the inhibitors is exposed to a water channel in TbrPDEB1, leading to fast unbinding.

A high-affinity, cis-on photoswitchable beta blocker to optically control β-adrenergic receptors in vitro and in vivo.

This study introduces (S)-Opto-prop-2, a second-generation photoswitchable ligand designed for precise modulation of β-adrenoceptor (βAR). Synthesised by incorporating an azobenzene moiety with propranolol, (S)-Opto-prop-2 exhibited a high PSS (photostationary state for cis isomer) percentage (∼90 %) and a favourable half-life (>10 days), facilitating diverse bioassay measurements. In vitro, the cis-isomer displayed substantially higher βAR binding affinity than the trans-isomer (1000-fold), making (S)-Opto-prop-2 one of the best photoswitchable GPCR (G protein-coupled receptor) ligands reported so far.

Synthesis and Pharmacological Characterization of New Photocaged Agonists for Histamine H and H Receptors.

The modulation of biological processes with light-sensitive chemical probes promises precise temporal and spatial control. Yet, the design and synthesis of suitable probes is a challenge for medicinal chemists. This article introduces a photocaging strategy designed to modulate the pharmacology of histamine H receptors (HR) and H receptors (HR).

Pharmacological Characterization and Radiolabeling of VUF15485, a High-Affinity Small-Molecule Agonist for the Atypical Chemokine Receptor ACKR3.

Atypical chemokine receptor 3 (ACKR3), formerly referred to as CXCR7, is considered to be an interesting drug target. In this study, we report on the synthesis, pharmacological characterization and radiolabeling of VUF15485, a new ACKR3 small-molecule agonist, that will serve as an important new tool to study this -arrestin-biased chemokine receptor. VUF15485 binds with nanomolar affinity (pIC = 8.