Optical Control of Lipid Rafts with Photoswitchable Ceramides

J Am Chem Soc. 2016 Oct 5;138(39):12981-12986. doi: 10.1021/jacs.6b07278. Epub 2016 Sep 26.

Abstract

Ceramide is a pro-apoptotic sphingolipid with unique physical characteristics. Often viewed as a second messenger, its generation can modulate the structure of lipid rafts. We prepared three photoswitchable ceramides, ACes, which contain an azobenzene photoswitch allowing for optical control over the N-acyl chain. Using combined atomic force and confocal fluorescence microscopy, we demonstrate that the ACes enable reversible switching of lipid domains in raft-mimicking supported lipid bilayers (SLBs). In the trans-configuration, the ACes localize into the liquid-ordered (Lo) phase. Photoisomerization to the cis-form triggers a fluidification of the Lo domains, as liquid-disordered (Ld) "lakes" are formed within the rafts. Photoisomerization back to the trans-state with blue light stimulates a rigidification inside the Ld phase, as the formation of small Lo domains. These changes can be repeated over multiple cycles, enabling a dynamic spatiotemporal control of the lipid raft structure with light.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ceramides / chemistry
  • Ceramides / metabolism*
  • Isomerism
  • Light*
  • Lipid Bilayers / chemistry
  • Lipid Bilayers / metabolism
  • Membrane Microdomains / radiation effects*
  • Optical Phenomena*

Substances

  • Ceramides
  • Lipid Bilayers