Self-assembled peptide nanostructures with stimuli-responsive features are promising
as functional materials. Despite extensive research efforts, water-soluble supramolecular
constructs that can interact with lipid membranes in a controllable way are still
challenging to achieve. Here, we have employed a short membrane anchor protein motif
(GLFD) and coupled it to a spiropyran photoswitch. Under physiological conditions,
these conjugates assemble into ∼3.5 nm thick, foil-like peptide bilayer morphologies.
Photoisomerization from the closed spiro (SP) form to the open merocyanine (MC) form
of the photoswitch triggers rearrangements within the foils. This results in substantial
changes in their membrane-binding properties, which also varies sensitively to lipid
composition, ranging from reversible nanofoil reformation to stepwise membrane adsorption.
The formed peptide layers in the assembly are also able to attach to various liposomes
with different surface charges, enabling the fusion of their lipid bilayers. Here,
SP-to-MC conversion can be used both to trigger and to modulate the liposome fusion
efficiency.
