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Title: Molecular-level interactions of nanodisc-forming copolymers dissected by EPR spectroscopy
Author(s): Eisermann, Jana
Hoffmann, Matthias
Schöffmann, Florian A.
Das, Manabendra
Vargas, Carolyn
Keller, Sandro
Hinderberger, Dariush
Issue Date: 2021
Type: Article
Language: English
Abstract: This study focuses on analyzing the noncovalent interaction patterns between three lipid-nanodisc-forming polymers and nitroxide radicals which are used as small organic tracer molecules. Besides the negatively charged polymers diisobutylene/maleic acid (DIBMA) and styrene/maleic acid (SMA) (2:1), the solvation behavior of a newly synthesized zwitterionic styrene/maleic amide sulfobetaine copolymer named SMA-sulfobetaine (SB) is characterized. The applied spin probes vary in their respective chemical structure, allowing the report of different local micropolarities and nanoscopic regions by recording temperature-dependent continuous-wave electron paramagnetic resonance (CW EPR) spectra. In combination with light scattering experiments, a nanoscopic interpretation of the dominant polymer/guest molecule interaction patterns is provided. The results indicate that in SMA and DIBMA, ionic interactions dominate the interaction patterns with other molecules. In SMA-SB, the zwitterionic side chains mainly induce a dynamic assembly with guest molecules due to weaker noncovalent interactions. Depending on the applied spin probe, temperature-dependent CW EPR measurements reveal nanoscopic cloud points depending on the interaction patterns with SMA-SB which can occur more than 20 °C below its macroscopically observed upper critical solution temperature. Finally, the detailed dissection of interaction patterns may provide a better understanding that may even allow tuning the polymers’ properties for use in lipid nanodisc formation.
Open Access: Open access publication
License: (CC BY-NC-ND 4.0) Creative Commons Attribution NonCommercial NoDerivatives 4.0(CC BY-NC-ND 4.0) Creative Commons Attribution NonCommercial NoDerivatives 4.0
Sponsor/Funder: Publikationsfonds MLU
Journal Title: Macromolecular Chemistry and Physics
Publisher: Wiley-VCH
Publisher Place: Weinheim
Volume: 222
Issue: 11
Original Publication: 10.1002/macp.202100051
Appears in Collections:Open Access Publikationen der MLU