Elliptical structure of phospholipid bilayer nanodiscs encapsulated by scaffold proteins: casting the roles of the lipids and the protein

Research output: Contribution to journalJournal articleResearchpeer-review

Nicholas Skar-Gislinge, Jens Bæk Simonsen, Kell Mortensen, Robert Krarup Feidenhans'l, Stephen G. Sligar, Birger Lindberg Møller, Thomas Bjørnholm, Lise Arleth

Phospholipid bilayers host and support the function of membrane proteins and may be stabilized in disc-like nanostructures, allowing for unprecedented solution studies of the assembly, structure, and function of membrane proteins (Bayburt et al. Nano Lett. 2002, 2, 853-856). Based on small-angle neutron scattering in combination with variable-temperature studies of synchrotron small-angle X-ray scattering on nanodiscs in solution, we show that the fundamental nanodisc unit, consisting of a lipid bilayer surrounded by amphiphilic scaffold proteins, possesses intrinsically an elliptical shape. The temperature dependence of the curvature of the nanodiscs prepared with two different phospholipid types (DLPC and POPC) shows that it is the scaffold protein that determines the overall elliptical shape and that the nanodiscs become more circular with increasing temperature. Our data also show that the hydrophobic bilayer thickness is, to a large extent, dictated by the scaffolding protein and adjusted to minimize the hydrophobic mismatch between protein and phospholipid. Our conclusions result from a new comprehensive and molecular-based model of the nanodisc structure and the use of this to analyze the experimental scattering profile from nanodiscs. The model paves the way for future detailed structural studies of functional membrane proteins encapsulated in nanodiscs.
Original languageEnglish
JournalJournal of the American Chemical Society
Volume132
Issue number39
Pages (from-to)13713–13722
Number of pages10
ISSN0002-7863
DOIs
Publication statusPublished - 2010

    Research areas

  • LIFE - Synthetic Biology, Small-angle scattering, Nano disc, lipids, membrane protein

ID: 32146788