Coupling chemical reactions to membrane curvature: A photochemical morphology switch

Max-Planck-Institut für Kolloid- und Grenzflächenforschung Am Mühlenberg, 14476 Golm, Germany

Received: 23 June 1999
Accepted: 17 September 1999

Abstract

We investigate the morphological response of giant phosphatidylcholine vesicles to a photochemical reaction taking place in the aqueous medium. We control the sign and magnitude of membrane curvature by inducing photoaquation of ferricyanide inside or outside the vesicle capsules. Curvature response is quantified via analysis of changes in vesicle shapes and in their thermal fluctuation spectra. As an underlying mechanism for the light-induced change in membrane curvature, we propose asymmetric charging of the internal or external monolayers by ion adsorption. Our study provides a specific example of a coupling between chemical reactions and interfacial geometry. The new photo-morphological effect may be used as a fast and reversible switch of membrane curvature.