Development of Enhanced Conformational Sampling Methods for GPCRs

Abstract

G protein‐coupled receptors (GPCRs) are known to possess multiple active conformational states in nature, however, studying these conformations is extremely challenging as majority of the functionally important conformations have high energy compared to the lowest energy conformation. We are developing a method called Enhanced Conformational Markov‐state Sampling in Membrane BiLayer Environment (EnCoMSeMBLE) that would enhance our search of the conformational landscape of GPCRs and that can be applied to a‐helical transmembrane proteins in general. It enables a level of conformational sampling not achievable by classical or accelerated molecular dynamics (MD) simulations or Markov‐State Models (MSM). This method combines brute force conformational sampling of helix‐helix interactions in the membrane with MD simulations and Markov‐State modeling to identify functionally important conformations. This method is being tested by application to the Glucagon Like peptide‐1 receptor (GLP1‐R), a class B GPCR, and the muscarinic acetylcholine M2 receptor, a class A GPCR, both of which have been crystallized in inactive as well as active conformations. The comparison of the activation landscapes of class A and class B GPCRs is beginning to provide key similarities and differences in activation across these very distinct GPCRs. This detailed understanding of the GPCR activation, enabled by our method, complements major structural biology efforts underway targeting GPCRs, where it is very challenging to map out the structural landscape and activation pathways of GPCRs.Support or Funding InformationBUILD PODER is supported through a grant from the National Institutes of General Medical Sciences (NIGMS), grants # # 8TL4GM11897This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.