Format

Send to

Choose Destination
J Chem Theory Comput. 2018 Mar 13;14(3):1706-1715. doi: 10.1021/acs.jctc.7b00983. Epub 2018 Feb 9.

Balancing Force Field Protein-Lipid Interactions To Capture Transmembrane Helix-Helix Association.

Author information

1
Department of Biochemistry , University of Oxford , South Parks Road , Oxford OX1 3QU , U.K.
2
Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases , National Institutes of Health , Bethesda , Maryland 20892-0520 , United States.

Abstract

Atomistic simulations have recently been shown to be sufficiently accurate to reversibly fold globular proteins and have provided insights into folding mechanisms. Gaining similar understanding from simulations of membrane protein folding and association would be of great medical interest. All-atom simulations of the folding and assembly of transmembrane protein domains are much more challenging, not least due to very slow diffusion within the lipid bilayer membrane. Here, we focus on a simple and well-characterized prototype of membrane protein folding and assembly, namely the dimerization of glycophorin A, a homodimer of single transmembrane helices. We have determined the free energy landscape for association of the dimer using the CHARMM36 force field. We find that the native structure is a metastable state, but not stable as expected from experimental estimates of the dissociation constant and numerous experimental structures obtained under a variety of conditions. We explore two straightforward approaches to address this problem and demonstrate that they result in stable dimers with dissociation constants consistent with experimental data.

PMID:
29424543
PMCID:
PMC5852462
DOI:
10.1021/acs.jctc.7b00983
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for American Chemical Society Icon for PubMed Central
Loading ...
Support Center