Phase separation in lipid bilayers

Condensed Matter lunchtime seminar

Phase separation in lipid bilayers

  • Event time: 1:00pm
  • Event date: 17th January 2005
  • Speaker: Vernita Gordon (University of Edinburgh)
  • Location: Room 2511,

Event details

Lipids are amphiphilic molecules which are found naturally in biological systems and can also be synthetically produced; the cell membrane, organelle membranes, and the surfactant lining the lungs have lipids as one of their main constituents. We study lipids in artificial membranes that form vesicles which are similar in size to eukaryotic cells. Our studies so far have focused on what happens when membranes made of a mixture of lipids phase-separate laterally to form microns-sized domains of different phases. The shapes of the domains of the solid-like ordered phases are a striking reflection of the ordering of the constituent lipids in those phases. Our observations also indicate strongly that some of these lipid mixtures show a little-studied ordered phase which seems to form only across two osculating bilayers, behavior reminiscent of some exotic smectic liquid crystal phases.
If time permits, I will also discuss work-in-progress on the size scales of the ordered-phase domains and on the way membrane adhesion has been seen to promote formation of ordered phases. The latter is of interest for technological and scientific reasons: it points the way toward a scheme for controlled patterning of vesicle surfaces, and it also indicates possibilities for developement of a model system to study what happens when cells adhere to and interact with each other and their extracellular environment.

This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..

Find out more about Condensed Matter lunchtime seminars.