Issue 40, 2010

Lipid-mediated interactions tune the association of glycophorin A helix and its disruptive mutants in membranes

Abstract

The specific and non-specific driving forces of helix association within membranes are still poorly understood. Here, we use coarse-grain molecular dynamics simulations to study the association behavior of glycophorin A and two disruptive mutants, T87F and a triple mutant of the GxxxG motif (G79LG83LG86L), embedded in a lipid membrane. Self-assembly simulations and the association free-energy profile confirm an energetically-favorable dimerized state for both the wild type and the mutants. The reduced association of the mutants compared to the wild type, as observed in experiments, can be justified from comparisons of the free energy profiles. Less-favorable proteinprotein interactions as well as disruption of lipid packing around the mutant dimers is responsible for their reduced association. The role of the non-specific “lipid-phobic” contribution appears to be as important as the specific “helix–helix” contribution. However, the differences between the wild type and mutants are subtle and our simulations predict a dimerization state not only for the wild-type glycophorin A, but also for these ‘disruptive’ mutants. Our results highlight the importance of both specific as well as non-specific driving forces in the association of transmembrane helices, and point to the need of more careful interpretation of experimental measurements.

Graphical abstract: Lipid-mediated interactions tune the association of glycophorin A helix and its disruptive mutants in membranes

Article information

Article type
Paper
Submitted
01 Apr 2010
Accepted
03 Aug 2010
First published
23 Aug 2010

Phys. Chem. Chem. Phys., 2010,12, 12987-12996

Lipid-mediated interactions tune the association of glycophorin A helix and its disruptive mutants in membranes

D. Sengupta and S. J. Marrink, Phys. Chem. Chem. Phys., 2010, 12, 12987 DOI: 10.1039/C0CP00101E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements