Visible‐Light Sensitized Isomerization in the Lipid Bilayer Enables Activation of a Transmembrane Transporter

Abstract

ABSTRACT Currently, there is major interest in embedding light‐responsive (supra)molecular systems in phospholipid bilayer membranes, for example, to control transmembrane transport processes. Most of these systems are operated by harmful UV‐light. Although in solution phase the isomerization of photoswitchable systems has been achieved using visible‐light‐absorbing photosensitizers, no cases are known yet of sensitized isomerization in a lipid bilayer environment. Herein, we show that the active isomer of a stiff‐stilbene based chloride transporter can be generated in situ by irradiation and energy transfer from a ruthenium tris(bipyridyl) complex. In the bilayer, this process is more efficient than in solution, as a benefit of the higher effective concentration of sensitizer and transporter upon confinement. Our work offers an approach to induce isomerization of membrane‐embedded systems by visible light, without the need of synthetic modification and loss of function or activity.