Phase Separation in Mixed Lipid Membranes
- Event time: 1:00pm
- Event date: 3rd March 2003
- Speaker: Paul Beales (University of Edinburgh)
- Location: Room 2511, James Clerk Maxwell Building (JCMB) James Clerk Maxwell Building Peter Guthrie Tait Road Edinburgh EH9 3FD GB
There has been a long-standing interest in lipid bilayers not least due to their relation to biological cell membranes. More recently there has been a lot of interest in bilayers of mixed lipid composition which exhibit heterogeneously mixed domains depending on conditions. These domains are thought to be analogous to ''rafts'' in biological membranes which, although there is only indirect evidence for their existence, are considered to be important in cell signalling. Phase diagrams exist for the phase separation in mixed lipid membranes with changing temperature and composition. I will summarize some of the existing literature on the phase separation in mixed phospholipid bilayers including a short discussion on the effects of the addition of cholesterol. The literature will also be discussed in relation to images obtained in COSMIC using multiphoton fluorescence microscopy of Giant Unilamellar Vesicles (GUVs) containing phospholipids with different head groups (DPPC/DPPE). GUVs are cell sized (5 - 50 microns) spherical bilayers which can be studied by direct optical techniques and are of most interest when considering the relevance of the results to ''raft'' formation in real biological membranes. I will finish with a brief description of plans for future experiments that will provide more accurate quantitative data.
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..