Lipid Interactions with Styrene-Maleic Acid Copolymers on Surfaces

Polymer stabilized lipid nanodiscs offer enormous potential as tools for enabling membrane protein structural studies & biophysics. Previously we studied discs formed using a poly(styrene-alt-maleic acid) (PSMA) copolymers synthesised using RAFT controlled radical polymerisations. The RAFT method is a living polymerisation allowing us to grow either an alternating styrene (S) and maleic acid (MA) segment first or a pure styrene section. We have tethered the RAFT agent to oxide surfaces allowing us to grow the polymer from the interface, and have demonstrated that the surface tethered polymer interacts strongly with lipid vesicles, pulling them out of suspension. Here we wish to use neutron reflectivity with contrast variation to determine the surface structures which develop in this system, and how these vary with the position of the S-MA vs S blocks relative to the surface.