613: In-depth characterization of tunable terpolymer series and its nanodisk particles

In-depth characterization of polymer-stabilized lipid nanodiscs

Zahn Stanvliet ¹, Gestél Kuyler ¹, Elaine Barnard ¹, Eva Bittrich ², Susanne Boye ², Ralf Schweins ³, Bert Klumperman ¹, Albena Lederer ^1,2

e-mail: zstanvliet@sun.ac.za

¹ Department of Chemistry and Polymer Science, University of Stellenbosch, PO Box XI, 7602, Stellenbosch, South Africa

² Center Macromolecular Structure Analysis, Leibniz-Instiut für Polymerforschung Dresden e.V., Hohe Strafle 6, D-01069 Dresden, Germany

³ DS/LSS Group, Institute Laue-Langevin, 6 Rue Jules Horowitz, F-38042 Grenoble Cedex 9, France

The study of membrane proteins (MP) remains a challenge, especially in a native membrane environment. The use of amphipathic copolymers serves as an alternative to the traditional detergent-based methods. In recent years, poly(styrene-co-maleic acid) (SMA) with a 2:1 styrene (hydrophobic) to maleic acid (hydrophilic) ratio has been deemed the “industry standard” for MP research.¹ A novel series of poly(styrene-co-maleic acid-co-(N-benzyl)maleimide) (BzAM) terpolymers have been developed, in which the hydrophilic/hydrophobic balance has been progressively changed, for the isolation of membrane proteins.² The BzAM series was designed to imitate SMA2:1 while incorporating the benefits of a well-defined molecular architecture. This will allow researchers to select the BzAM polymer with hydrophilic/hydrophobic characteristics best suited to encapsulating their specific MP of interest. It is of considerable interest to conduct an in-depth characterization of these polymers and their corresponding nanodiscs. Advanced separation techniques such as asymmetric flow field-flow fractionation (AF4) and size exclusion chromatography (SEC) with multi-detection will be employed to separate free polymer from nanodiscs, enabling a more comprehensive understanding of their architecture and membrane-solubilizing properties.^3–6 Small-angle neutron scattering (SANS) will be used to further elucidate the internal structure of the nanodiscs. Ultimately, this study aims to investigate how factors such as backbone flexibility and charge density influence nanodisc morphology. Understanding the BzAM series, along with their nanodisc morphologies and assembly mechanisms under varying conditions, will support the development of more effective strategies for membrane solubilization.

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