ausblenden:
Schlagwörter:
lipid membrane; vesicle; azobenzene; photoswitch; molecular dynamics;
Zusammenfassung:
Biomembranes are constantly remodeled and in cells, these processes are
controlled and modulated by an assortment of membrane proteins. Here, we show that such
remodeling can also be induced by photo-responsive molecules. We demonstrate the
morphological control of giant vesicles in the presence of a water-soluble orthotetrafluoroazobenzene
photoswitch (F-azo) and show that the shape transformations are based
on an increase in membrane area and generation of spontaneous curvature. The vesicles
exhibit budding and the buds can be retracted by using light of a different wavelength. In the
presence of F-azo, the membrane area can increase by more than 5% as assessed from vesicle
electrodeformation. To elucidate the underlying molecular mechanism and the partitioning of
F-azo in the membrane, we used molecular dynamics simulations. Comparison with
theoretically calculated shapes reveals that the area difference between the two leaflets of the
vesicle membrane is not constrained during the budding process and that the experimentally
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observed shapes are well described by the spontaneous curvature model. Our results show
that exo- and endocytotic events can be controlled by light and that these photo-induced
processes provide an attractive method to change membrane area and morphology.
