Neutron reflectometry reveals how membrane lipids modulate chondroitin sulphate binding at the cell surface
DRA lecture held by Assoc. Prof. Alessandra Luchini, PhD
Department of Physics and Geology, University of Perugia, Perugia, Italy
The cell surface — the interface between the plasma membrane (PM) and the extracellular matrix (ECM) — is difficult to characterize directly, since standard extraction protocols disrupt its native structure. Structural knowledge therefore relies on membrane models, particularly supported lipid bilayers (SLBs), where neutron reflectometry (NR) resolves lipid organization and biomolecule interactions at Å resolution. Recently, we designed SLBs composed of both synthetic lipids and natural lipid extracts to mimic from basic to more complex features of the mammalian PM. These SLBs were used to study how the plasma membrane lipid composition can affect the adsorption and location of a target ECM component: chondroitin sulphate (CS). CS is among the most abundant polysaccharides and typically located in the proximity of the PM. Despite CS being involved in several biological process and more recently also being identified as a cancer biomarker, its interaction with the lipids within the PM remains largely unexplored. NR experiments supported by molecular dynamics simulations, and other experimental techniques, revealed that CS adsorption is reduced in the presence of negatively charged lipids and enhanced by cholesterol. Altogether this study illustrates how variation in the PM composition can sensibly affect the structural architecture of ECM components such as CS, with potential implication on how the cell communicates with the surrounding environment.
The lecture is organised on behalf of the graduate programme in pharmaceutical sciences, Drug Research Academy, by Tenure Track Assistant Professor Federica Sebastiani, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen.
The DRA lecture is free of charge and open for attendance by all interested parties. It is not necessary to pre-register.