Investigating lipid and polymer exchange processes in protein-containing polymer-stabilised nanodiscs

Poly-Styrene-co-Maleic Acid Lipid Particles (SMALPs) are discoidal self-assembled nanoparticles containing a central lipid bilayer core stabilised by a radial amphipathic polymer belt, used to extract membrane proteins directly from host cell membranes complete with annular lipids. Recent studies from ourselves and others have shown that lipids and polymers within SMALPs rapidly exchange with other SMALPs in bulk solution, phospholipid monolayers, and phospholipid bilayers. Here, we propose to use neutron reflectometry, with selective deuteration and solution isotopic contrast variation to investigate the influence of encapsulated proteins and native lipids on the rates and extents of exchange processes between SMALPs and lipid bilayers at the silicon-water interface. This information will be of great benefit to capitalise on both the biotechnological and therapeutic potential of SMALPs.