Study of the affinities of allosteric ligands for G protein-coupled receptors by the measurement of cellular signaling

2017 Fiscal Year Final Research Report

• Project/Area Number: 26460092
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Pharmacology in pharmacy
• Research Institution: Showa Women's University (2017); Juntendo University (2015-2016); The University of Tokyo (2014)
• Principal Investigator: Suga Hinako 昭和女子大学, 生活科学部, 准教授 (50261186)
• Research Collaborator: Ehlert FJ. カリフォルニア大学, アーバイン校・医学部, 教授
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: GPCR / Gタンパク質共役受容体 / ムスカリン受容体 / アセチルコリン / リガンドバイアス / アロステリックリガンド / 細胞応答 / リガンド

Outline of Final Research Achievements

I explored a novel method to analyze affinities of allosteric ligands by measuring a response downstream in the signaling pathway, without using radioligands. I measured carbamylcholine (agonist)-induced signaling responses of cells expressing wild type M2 muscarinic receptor or a constitutively active mutant of M2 muscarinic receptor after partial receptor inactivation by atropine (antagonist) using TGFα shedding assay.
I'm analyzing the data and getting estimates of the isomerization constant of the unoccupied receptor, the sensitivity constant of the signaling pathway, and the more empirical parameters of the receptor population including the observed affinities and efficacies of allosteric and orthosteric ligands, including inverse agonists, and the efficacy of the unoccupied receptor (i.e., constitutive activity). My method will provide a more meaningful analysis of structure-activity relationships, and an absolute measure of agonist bias.

Free Research Field

受容体薬理学