A major challenge for biophysical studies of membrane
proteins is obtaining stable, homogenous samples. Traditional
detergent solubilization and liposome-based methods of
reconstitution may lead to protein inactivation, heterogeneous
and polydisperse sized particles, and sample aggregation.[
1] While membrane scaffold protein (MSP) stabilized
nanodiscs have facilitated the formation of monodisperse
protein samples,[2] a drawback is the detergent-based preparation
method. Here we present a physicochemical characterization
of polymer-stabilized lipid particles termed Lipodisq,
a novel nanosized lipid-based platform capable of incorporating
membrane proteins.[3] The polymers used in the
Lipodisq technology can solubilize commonly used lipids
such as dimyristoylphosphatidylcholine (DMPC) without the
use of detergents. The small size of Lipodisq (diameter of
around 9–10 nm at pH 7.4) renders them potentially suitable
for many biophysical methodologies, including electron paramagnetic
resonance (EPR) and nuclear magnetic resonance
(NMR) spectroscopies, electron microscopy (EM), and
circular dichroism (CD) spectroscopy.