S. Werner, H. Ebert, B.-D. Lechner, Frank Lange, Anja Achilles, R. Bärenwald, S. Poppe, A. Blume, K. Saalwächter, C. Tschierske, K. Bacia.
Dendritic Domains with Hexagonal Symmetry Formed by
X-Shaped Bolapolyphiles in Lipid Membranes.
Chem. Eur. J. 21, 8840-8850 (2015).
A novel class of bolapolyphile (BP) molecules are
shown to integrate into phospholipid bilayers and self-assemble
into unique sixfold symmetric domains of snowflakelike
dendritic shapes. The BPs comprise three philicities:
a lipophilic, rigid, π–π stacking core; two flexible lipophilic
side chains; and two hydrophilic, hydrogen-bonding head
groups. Confocal microscopy, differential scanning calorimetry,
XRD, and solid-state NMR spectroscopy confirm BP-rich
domains with transmembrane-oriented BPs and three to
four lipid molecules per BP. Both species remain well organized
even above the main 1,2-dipalmitoyl-sn-glycero-3-phosphocholine
transition. The BP molecules only dissolve in the
fluid membrane above 70 °C. Structural variations of the BP
demonstrate that head-group hydrogen bonding is a prerequisite
for domain formation. Independent of the head
group, the BPs reduce membrane corrugation. In conclusion,
the BPs form nanofilaments by p stacking of aromatic cores,
which reduce membrane corrugation and possibly fuse into
a hexagonal network in the dendritic domains.