Spontaneous transmembrane helix insertion thermodynamically mimics translocon-guided insertion
Ulmschneider, M.B. and Ulmschneider, J.P. and Schiller, N. and Wallace, Bonnie A. and von Heijne, G. and White, S.H. (2014) Spontaneous transmembrane helix insertion thermodynamically mimics translocon-guided insertion. Nature Communications 5 , p. 4863. ISSN 2041-1723.
Abstract
The favourable transfer free energy for a transmembrane (TM) α-helix between the aqueous phase and lipid bilayer underlies the stability of membrane proteins. However, the connection between the energetics and process of membrane protein assembly by the Sec61/SecY translocon complex in vivo is not clear. Here, we directly determine the partitioning free energies of a family of designed peptides using three independent approaches: an experimental microsomal Sec61 translocon assay, a biophysical (spectroscopic) characterization of peptide insertion into hydrated planar lipid bilayer arrays, and an unbiased atomic-detail equilibrium folding-partitioning molecular dynamics simulation. Remarkably, the measured free energies of insertion are quantitatively similar for all three approaches. The molecular dynamics simulations show that TM helix insertion involves equilibrium with the membrane interface, suggesting that the interface may play a role in translocon-guided insertion.
Metadata
| Item Type: | Article |
|---|---|
| Keyword(s) / Subject(s): | Biological sciences, Cell biology |
| School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
| Research Centres and Institutes: | Bioinformatics, Bloomsbury Centre for (Closed), Structural Molecular Biology, Institute of (ISMB) |
| Depositing User: | Administrator |
| Date Deposited: | 15 Sep 2014 09:15 |
| Last Modified: | 02 Aug 2023 17:12 |
| URI: | https://eprints.bbk.ac.uk/id/eprint/10518 |
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