A Dynamic, Split-Luciferase-Based Mini-G Protein Sensor to Functionally Characterize Ligands at All Four Histamine Receptor Subtypes

International Journal of Molecular Sciences

Steffen Pockes¹  Ulla Seibel¹  Sebastian Pitzl¹  Andrea Strasser¹  Denise Mönnich¹  Carina Höring¹  Lukas Grätz¹  Katharina Tropmann¹  Günther Bernhardt¹ 

[1] Institute of Pharmacy, Faculty of Chemistry and Pharmacy, University of Regensburg, 93040 Regensburg, Germany;

关键词: histamine receptors;    split-luciferase complementation (SLC);    mini-G protein recruitment;    G protein-coupled receptors (GPCRs);    histamine receptor ligands;    bioluminescence;   

DOI  :  10.3390/ijms21228440

来源: DOAJ

【 摘 要 】

In drug discovery, assays with proximal readout are of great importance to study target-specific effects of potential drug candidates. In the field of G protein-coupled receptors (GPCRs), the determination of GPCR-G protein interactions and G protein activation by means of radiolabeled GTP analogs ([³⁵S]GTPγS, [γ-³²P]GTP) has widely been used for this purpose. Since we were repeatedly faced with insufficient quality of radiolabeled nucleotides, there was a requirement to implement a novel proximal functional assay for the routine characterization of putative histamine receptor ligands. We applied the split-NanoLuc to the four histamine receptor subtypes (H₁R, H₂R, H₃R, H₄R) and recently engineered minimal G (mini-G) proteins. Using this method, the functional response upon receptor activation was monitored in real-time and the four mini-G sensors were evaluated by investigating selected standard (inverse) agonists and antagonists. All potencies and efficacies of the studied ligands were in concordance with literature data. Further, we demonstrated a significant positive correlation of the signal amplitude and the mini-G protein expression level in the case of the H₂R, but not for the H₁R or the H₃R. The pEC₅₀ values of histamine obtained under different mini-G expression levels were consistent. Moreover, we obtained excellent dynamic ranges (Z’ factor) and the signal spans were improved for all receptor subtypes in comparison to the previously performed [³⁵S]GTPγS binding assay.

【 授权许可】

Unknown