Evaluation of Drug Responses to Human β2AR Using Native Mass Spectrometry

Michiko Tajiri; Shunsuke Imai; Tsuyoshi Konuma; Keiko Shimamoto; Ichio Shimada; Satoko Akashi

doi:10.1021/acsomega.3c02737

Evaluation of Drug Responses to Human β₂AR Using Native Mass Spectrometry

ACS Omega. 2023 Jun 28;8(27):24544-24551. doi: 10.1021/acsomega.3c02737. eCollection 2023 Jul 11.

Authors

Michiko Tajiri¹, Shunsuke Imai², Tsuyoshi Konuma¹, Keiko Shimamoto³, Ichio Shimada^{2

4}, Satoko Akashi¹

Affiliations

¹ Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
² Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
³ Suntory Foundation for Life Sciences, 8-1-1 Seikadai, Seika-cho, Soraku-gun, Kyoto 619-0284, Japan.
⁴ Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4 Kagamiyama, Higashi, Hiroshima City, Hiroshima 739-8528, Japan.

Abstract

We aimed to develop a platform to rapidly investigate the responses of agonists and antagonists to G-protein-coupled receptors (GPCRs) using native mass spectrometry (MS). We successfully observed the ligand-bound human β₂ adrenergic receptor (hβ₂AR); however, it was challenging to quantitatively discuss drug efficacy from MS data alone. Since ligand-bound GPCRs are stabilized by the Gα subunit of G proteins on the membrane, mini-G_s and nanobody80 (Nb80) that can mimic the Gα interface of the GPCR were utilized. Ternary complexes of hβ₂AR, ligand, and mini-G_s or Nb80 were prepared and subjected to native MS. We found a strong correlation between the hβ₂AR-mini-G_s or -Nb80 complex ratio observed in the mass spectra and agonist/antagonist efficacy obtained using a cell-based assay. This method does not require radioisotope labeling and would be applicable to the analysis of other GPCRs, facilitating the characterization of candidate compounds as GPCR agonists and antagonists.