Title of my PhD project: Supported double bilayers, a platform to assess the stability of biomembranes and to study membrane-ligand interactions
Project duration: September 2016 - September 2020
Project Introduction: The Structure, mechanical properties and stability of lipid membranes is vital for living cells. Topologically complex and dynamic phenomena, such as endocytosis and exocytosis or organelle morpholgeneses, require that membranes are on the edge of stability and this potentially clashes with their barrier function. Understanding nature's solution - Molecular complexity - is urgently needed. To do so, I want to recreate biological double membranes to explore the physical properties and changes in physical properties of membranes upon interaction with biomolecules.
Project aim: During my thesis I want to develop and employ an experimental platform that allows determination of the properties and structural integrity of biomembranes, challenged by various pertubing stimuli, in particular interaction of biomolecules with the membrane. The platform will consist of a supported double lipid membrane configuration in a flow cell. A Total-Internal-Reflection-Fluorescence (TIRF) Microscopye will be used to probe the the outer bilayer and how it responds to external stimuli and changes in the environment. We have a dedicated force microscope (AFM) that can be mounted on top of the TIRF microscope so that simultaneously force measurements can be performed to obtain mechanical information and to perturb the outer membrane.
Once the platform has been established, progressive levels of membrane complexity can be explored, from single component systems to multicomponent and asymmetric lipid membranes. We will push and pull on the membrane in different ways, using AFM tips as well as colloid probe particles, to get mechanical information. In addition, we will perform single molecule force spectroscopy in which a biomolecule is covalently attached to the AFM tip, to learn about the way macromolecules interact with the bilayer. We will investigate the topological stability of the membrane by exposing it to perturbing external stimuli, involving edge-active agents, antimicrobial peptides and nanoparticles.