The adenosine receptors are proteins that reside in the extracellular membranes of cells. Activation of adenosine receptors plays a role in many physiological and pathological processes, such as... Show moreThe adenosine receptors are proteins that reside in the extracellular membranes of cells. Activation of adenosine receptors plays a role in many physiological and pathological processes, such as immune responses and cancers. Binding the adenosine receptors by either agonists or antagonists is therefore an interesting strategy currently carried out in multiple drug discovery programs. In order to make such drug discovery programs successful, our general understanding of adenosine receptor functioning should be improved. In that sense, new molecular tools can aid studies towards the adenosine receptors, for example by aiding the detection of receptor proteins or deciphering activation pathways. In this thesis, the development (synthesis, pharmacological evaluation and biological application) of chemical probes as molecular tool compounds for the adenosine receptors is described. This comprises the development of a covalent ligand for the adenosine A2B receptor, affinity-based probes for the adenosine A1 and A3 receptors and a ligand-directed probe for the adenosine A2B receptor. These chemical probes will aid future studies towards the roles of the A2B, A1 and A3 receptors in various conditions. Show less
Beerkens, B.L.H.; Snijders, I.M.; Snoeck, J.; Liu, R.; Tool, A.T.J.; Le Dévédec, S.E.; ... ; Es, D. van der 2023
The adenosine A3 receptor (A3AR) is a G protein-coupled receptor (GPCR) that exerts immunomodulatory effects in pathophysiological conditions such as inflammation and cancer. Thus far, studies... Show moreThe adenosine A3 receptor (A3AR) is a G protein-coupled receptor (GPCR) that exerts immunomodulatory effects in pathophysiological conditions such as inflammation and cancer. Thus far, studies toward the downstream effects of A3AR activation have yielded contradictory results, thereby motivating the need for further investigations. Various chemical and biological tools have been developed for this purpose, ranging from fluorescent ligands to antibodies. Nevertheless, these probes are limited by their reversible mode of binding, relatively large size, and often low specificity. Therefore, in this work, we have developed a clickable and covalent affinity-based probe (AfBP) to target the human A3AR. Herein, we show validation of the synthesized AfBP in radioligand displacement, SDS-PAGE, and confocal microscopy experiments as well as utilization of the AfBP for the detection of endogenous A3AR expression in flow cytometry experiments. Ultimately, this AfBP will aid future studies toward the expression and function of the A3AR in pathologies. Show less
Beerkens, B.L.H.; Koc, C.; Liu, R.; Florea, B.I.; Le Dévédec, S.E.; Heitman, L.H.; ... ; Es, D. van der 2022
G protein-coupled receptors (GPCRs) have been known for decades as attractive drug targets. This has led to the development and approval of many ligands targeting GPCRs. Although ligand binding... Show moreG protein-coupled receptors (GPCRs) have been known for decades as attractive drug targets. This has led to the development and approval of many ligands targeting GPCRs. Although ligand binding effects have been studied thoroughly for many GPCRs, there are multiple aspects of GPCR signaling that remain poorly understood. The reasons for this are the difficulties that are encountered upon studying GPCRs, for example, a poor solubility and low expression levels. In this work, we have managed to overcome some of these issues by developing an affinity-based probe for a prototypic GPCR, the adenosine A1 receptor (A1AR). Here, we show the design, synthesis, and biological evaluation of this probe in various biochemical assays, such as SDS-PAGE, confocal microscopy, and chemical proteomics. Show less
Beerkens, B.L.H.; Wang, X.; Avgeropoulou, M.; Adistia, L.N.; Veldhoven, J.P.D. van; Jespers, W.; ... ; Es, D. van der 2022
