Membrane proteins serve as the primary gateways for molecular influx and efflux in cells, making them potential drug targets and key players in drug resistance. However, purification and biophysical characterization of membrane proteins remain challenging, as these processes require their extraction from the membrane while preserving structure, function, and activity. Styrene-maleic acid co-polymers (SMALPs) have emerged as a promising solution for isolating membrane proteins while maintaining portions of the native membrane. Despite their potential, SMALPs are not widely adopted due to their comparatively low-efficiency in membrane protein extraction relative to detergents. In this study, we employ molecular dynamics (MD) simulations to uncover the molecular determinants of SMALP behavior. Using constant-pH molecular dynamics (CpHMD) simulations, we investigate how carboxyl protonation states vary depending on their chemical surroundings. Additionally, coarse-grained MD simulations of SMALP nanoparticles with membrane proteins reveal their interactions with lipids. Our simulations provide valuable insights into SMALP behavior and lay the groundwork for optimizing SMALP composition, ultimately improving membrane protein isolation techniques. The overarching goal of this project is to apply the recent advances in protein structure prediction and design to integrate membrane proteins models into our SMALPed membrane systems. By applying cutting-edge computational tools and structure prediction, we can provide atomic coordinates and dynamic profiles that illuminate membrane protein interactions within SMALPs. This approach will enable a more comprehensive understanding of the biological and pharmacological complexity of membrane proteins, providing a path to further innovation in membrane protein research and drug discovery.
Abreu et al. (Sun,) studied this question.