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Analysis Of Ligand Bias In Functional Studies Involving The Allosteric Modulation Of G Protein- Coupled Receptors, Frederick J. Ehlert, Michael T. Griffin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Introduction

The affinity constants of a ligand for active and inactive states of a receptor ultimately determine its capacity to activate downstream signaling events. In this report, we describe a reverse-engineering strategy for estimating these microscopic constants.

Methods

Our approach involves analyzing responses measured downstream in the signaling pathway of a G protein-coupled receptor under conditions of allosteric modulation and reduced receptor expression or partial receptor inactivation. The analysis also yields 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 …