Nanodiscs are powerful tools for investigating membrane proteins: They enable experimentalists to get these hydrophobic macromolecules into solution, while at the same time keep them in a native-like lipid bilayer environment. Little is known in atomistic detail about the structural organisation of proteins and lipids in nanodiscs. We use molecular dynamics (MD) simulations to probe the structure and dynamics of both empty and protein-loaded nanodiscs. We also study the properties of membrane proteins and their associated lipids inside nanodisc environments.
Nanodisc-embedded ABC transporter.
Our simulations of a nanodisc-embedded ABC transporter show that even as little as 22 lipids can isolate the membrane protein from the surrounding scaffold proteins and the aqueous environment. Lipids tilt to cover more surface of the embedded protein in the plane of the nanodisc, yielding a thinner membrane. This work has implications for the development and usage of nanodisc techniques and provides atomic resolution information that could not be obtained otherwise.