title: Self-Assembly of X-Shaped Bolapolyphiles in Lipid Membranes: Solid-State NMR Investigations.
abstract: A novel class of rigid-rod bolapolyphilic molecules with three philicities (rigid aromatic core, mobile aliphatic side chains, polar end groups) has recently been demonstrated to incorporate into and span lipid membranes, and to exhibit a rich variety of self-organization modes, including macroscopically ordered snowflake structures with 6-fold symmetry. In order to support a structural model and to better understand the self-organization on a molecular scale, we here report on proton and carbon-13 high-resolution magic-angle spinning solid-state NMR investigations of two different bolapolyphiles (BPs) in model membranes of two different phospholipids (DPPC, DOPC). We elucidate the changes in molecular dynamics associated with three new phase transitions detected by calorimetry in composite membranes of different composition, namely, a change in π-π-packing, the melting of lipid tails associated with the superstructure, and the dissolution and onset of free rotation of the BPs. We derive dynamic order parameters associated with different H-H and C-H bond directions of the BPs, demonstrating that the aromatic cores are well packed below the final phase transition, showing only 180° flips of the phenyl ring, and that they perform free rotations with additional oscillations of the long axis when dissolved in the fluid membrane. Our data suggests that BPs not only form ordered superstructures, but also rather homogeneously dispersed π-packed filaments within the lipid gel phase, thus reducing the corrugation of large vesicles.
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Achilles
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Ruth
authors.initials: R
authors.lastname: Bärenwald
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Bob-Dan
authors.initials: BD
authors.lastname: Lechner
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Werner
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Helgard
authors.initials: H
authors.lastname: Ebert
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Tschierske
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Blume
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Bacia
authors.affiliation: Institut für Physik - NMR, ‡Institut für Chemie - Physikalische Chemie, §ZIK HALOmem, and ∥Institut für Chemie - Organische Chemie, Martin-Luther-Universität Halle-Wittenberg , D-06120 Halle, Germany.
authors.forename: Kay
authors.initials: K
authors.lastname: Saalwächter
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D056004:Molecular Dynamics Simulation; D044367:Phase Transition; D010713:Phosphatidylcholines / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D010713:Phosphatidylcholines; D015060:1,2-Dipalmitoylphosphatidylcholine; C017251:1,2-oleoylphosphatidylcholine