Cell Chemical Biology, Volume 25, Issue 3, 309 - 317.e4
Abstract:
The interactions between proteins and biological membranes are important for drug development, but remain notoriously refractory to structural investigation. We combine non-denaturing mass spectrometry (MS) with molecular dynamics (MD) simulations to unravel the connections among co-factor, lipid, and inhibitor binding in the peripheral membrane protein dihydroorotate dehydrogenase (DHODH), a key anticancer target. Interrogation of intact DHODH complexes by MS reveals that phospholipids bind via their charged head groups at a limited number of sites, while binding of the inhibitor brequinar involves simultaneous association with detergent molecules. MD simulations show that lipids support flexible segments in the membrane-binding domain and position the inhibitor and electron acceptor-binding site away from the membrane surface, similar to the electron acceptor-binding site in respiratory chain complex I. By complementing MS with MD simulations, we demonstrate how a peripheral membrane protein uses lipids to modulate its structure in a similar manner as integral membrane proteins.
License type:
http://creativecommons.org/licenses/by-nc-nd/4.0/
Funding Info:
The computations were performed on resources provided by SNIC through Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX) under Project SNIC 2017/7–15 and SNIC 2017/1–188. ML is supported by an Ingvar Carlsson Award from the Swedish Foundation for Strategic Research and a KI facultyfunded Career Position. J.G. is a Junior Research Fellow of The Queen’s College, University of Oxford. E.G.M. holds a Marie Sk1odowska Curie International Career Grant from the European Commission and the Swedish Research Council (2015-00559). S.L. and D.P.L. acknowledge support from the Swedish Research Council (VR), Cancerfonden, Barncancerfonden, and Karolinska Institutet. This work is supported by an EPSRC Institutional Sponsorship 2016 award (EP/P511377/1).