Molecule of the Month: Nanodiscs and HDL
Nanodiscs conveniently package a small piece of membrane for experimental studies.
Nanodiscs and NMR
Exploring the Structure
MT1-MMP and nanodisc
Nanodiscs are engineered by starting with natural apolipoproteins, then changing the length of the chain to surround a disc of a desired size. The engineered proteins are termed MSP (membrane scaffolding proteins), and like apolipoproteins, they form an alpha-helical structure that places an array of hydrophobic amino acids (shown here in white) on the inner surface of the ring. These amino acids stabilize the hydrophobic portions of the lipids in the membrane. To explore this structure in more detail, click on the image for an interactive JSmol.
Topics for Further Discussion
- Try searching for “nanodisc” at the EMDataResource to see the EM maps of these proteins, and notice that the nanodisc itself is often not well resolved.
- Try searching for “apolipoprotein” at the main RCSB PDB website to see some structures of these proteins when they are not bound to lipids.
- You can see a structure of the protein portion of a disc-shaped HDL in PDB entry 2n5e.
September 2019, David Goodsellhttp://doi.org/10.2210/rcsb_pdb/mom_2019_9