Details

Autor(en) / Beteiligte

• Bouzo-Lorenzo, Monica
• Stoddart, Leigh A
• Xia, Lizi
• IJzerman, Adriaan P
• Heitman, Laura H
• Briddon, Stephen J
• Hill, Stephen J

Titel

A live cell NanoBRET binding assay allows the study of ligand-binding kinetics to the adenosine A 3 receptor

Ist Teil von

• Purinergic signalling, 2019-06, Vol.15 (2), p.139

Ort / Verlag

Netherlands

Erscheinungsjahr

2019

Quelle

MEDLINE

Beschreibungen/Notizen

• There is a growing interest in understanding the binding kinetics of compounds that bind to G protein-coupled receptors prior to progressing a lead compound into clinical trials. The widely expressed adenosine A receptor (A AR) has been implicated in a range of diseases including immune conditions, and compounds that aim to selectively target this receptor are currently under development for arthritis. Kinetic studies at the A AR have been performed using a radiolabelled antagonist, but due to the kinetics of this probe, they have been carried out at 10 °C in membrane preparations. In this study, we have developed a live cell NanoBRET ligand binding assay using fluorescent A AR antagonists to measure kinetic parameters of labelled and unlabelled compounds at the A AR at physiological temperatures. The kinetic profiles of four fluorescent antagonists were determined in kinetic association assays, and it was found that XAC-ser-tyr-X-BY630 had the longest residence time (RT = 288 ± 62 min) at the A AR. The association and dissociation rate constants of three antagonists PSB-11, compound 5, and LUF7565 were also determined using two fluorescent ligands (XAC-ser-tyr-X-BY630 or AV039, RT = 6.8 ± 0.8 min) as the labelled probe and compared to those obtained using a radiolabelled antagonist ([ H]PSB-11, RT = 44.6 ± 3.9 min). There was close agreement in the kinetic parameters measured with AV039 and [ H]PSB-11 but significant differences to those obtained using XAC-S-ser-S-tyr-X-BY630. These data indicate that selecting a probe with the appropriate kinetics is important to accurately determine the kinetics of unlabelled ligands with markedly different kinetic profiles.