Self-assembly of nanoscale particles with biosurfactants and membrane scaffold proteins

- Production of nanoscale particles with membrane scaffold proteins (MSPs) and rhamnolipid biosurfactants was shown.
- Di-rhamnolipid was shown to form particles upon assembly with the detergent dialysis method according to Stephen G. Sligar.
- Mono-rhamnolipids did not result in formation of particles, likely due to differing detergent properties compared to DPPC.

Nanodiscs are membrane mimetics which may be used as tools for biochemical and biophysical studies of a variety of membrane proteins. These nanoscale structures are composed of a phospholipid bilayer held together by an amphipathic membrane scaffold protein (MSP). In the past, nanodiscs were successfully assembled with membrane scaffold protein 1D1 and 1,2-dipalmitoyl-sn-glycero-3-phosphorylcholine with a homogeneous diameter of ∼10 nm. In this study, the formation of nanoscale particles from MSP1D1 and rhamnolipid biosurfactants is investigated. Different protein to lipid ratios of 1:80, 1:90 and 1:100 were used for the assembly reaction, which were consecutively separated, purified and analyzed by size-exclusion chromatography (SEC) and dynamic light scattering (DLS). Size distributions were measured to determine homogeneity and confirm size dimensions. In this study, first evidence is presented on the formation of nanoscale particles with rhamnolipid biosurfactants and membrane scaffold proteins.