Nanodiscs versus Macrodiscs for NMR of Membrane Proteins

Abstract

It is challenging to find membrane mimics that stabilize the native structure, dynamics, and functions of membrane proteins. In a recent advance, nanodiscs have been shown to provide a bilayer environment compatible with solution NMR. Increasing the lipid to “belt” peptide ratio expands their diameter, slows their reorientation rate, and enables the protein-containing discs to be aligned in a magnetic field for Oriented Sample solid-state NMR. Here, we compare the spectroscopic properties of membrane proteins with between one and seven trans-membrane helices in q=0.1 isotropic bi-celles, ∼10 nm diameter isotropic nanodiscs, ∼30 nm diameter magnetically aligned macrodiscs, and q=5 bicelles.

BcsA and BcsB form the catalytically active core of bacterial cellulose synthase sufficient for in vitro cellulose synthesis

“…S4), which are edge-stabilized, planar lipid bilayer discs ∼10 nm in diameter (37). At this size, each ND most likely contains a single BcsA-B complex (38).…”

Smaller Nanodiscs are Suitable for Studying Protein Lipid Interactions by Solution NMR

“…An interesting observation from this study is that nanodiscs with varied particle sizes can be obtained by fine-tuning the ratio of scaffold protein to lipids. Nanodiscs with larger diameter may not be useful for solution NMR studies, but could be helpful for other biochemical or biophysical studies, as exemplified in the application of solid state NMR [14].…”

The Styrene-Maleic Acid Copolymer: A Versatile Tool in Membrane Research

“…The diameter of nanodiscs is typically in the order of ~10 nm, but generation of specific MSP variants allows the formation of smaller (~6-7 nm) (Hagn et al 2013;Wang et al 2015) and larger (16-17 nm) (Grinkova et al 2010) nanodiscs. Furthermore, the use of different apolipoproteins or derived peptides and the variation of the peptide/protein-lipid ratio enable the preparation of larger particles (Chromy et al 2007;Park et al 2011). This control over size renders them excellent tools in many biophysical methods for structural and functional characterization of MPs.…”

“…However, both solutionand solid-state NMR approaches have been established for MSP nanodiscs (Ding et al 2015) and therefore, in principle, should also be possible for proteins in native nanodiscs. An alternative NMR approach using aligned systems, as reported for relatively large bicelles (Howard and Opella 1996), unfortunately does not appear to be feasible, since neither standard MSP-nanodiscs nor SMALPs tend to align in magnetic fields: in both cases isotropic peaks in 31 P NMR are observed that suggest fast reorientation of the particles in all directions (Park et al 2011;Vargas et al 2015;Zhang et al 2015). …”