Biophysical Studies Of Styrene-Maleic Acid Copolymer Stabilized Membrane Mimetics

Diane Yu, University of Connecticut - Storrs



Traditional methods of isolating membrane proteins involve the use of detergents that destabilize the membrane environment. Biophysical studies of membrane proteins are challenged by the requirement of a stable membrane platform. Lipodisq® nanoparticles are novel membrane mimetics that consist of 3:1 styrene-maleic acid copolymer encircling phospholipids to form discoidal species on the order of 10 nm in diameter. Bacteriorhodopsin was previously incorporated into Lipodisq® nano-particles from its native purple membrane without the addition of detergent. In this study, dynamic light scattering was used to investigate the stability of empty Lipodisq® nano-particles over time. These data show that Lipodisq® nano-particles are stable for up to 48 hours at both 20 and 30°C. At each temperature, Lipodisq® nano-particles consist of greater than 95% of the total volume of the sample. Therefore, it is reasonable to investigate the properties of lipids and membrane proteins in Lipodisq® nano-particles using experimental techniques that require up to 48 hours.