Invited Paper AS-MoA1
Surface-based Model Systems of Biomolecular Hydrogels - From Supramolecular Organization and Dynamics to Biological Function

Monday, October 31, 2011, 2:00 pm, Room 102

Nature has evolved complex materials that are exquisitely designed to perform specific functions. Certain proteins and glycans self-organize in vivo into soft and dynamic, strongly hydrated gel-like matrices. Illustrative examples of such biomolecular hydrogels are cartilage and mucus. Although biomolecular hydrogels are ubiquitous in living organisms and fulfill fundamental biological tasks, we have today a very limited understanding of their internal organization, and how they function. The main reason is that this type of assemblies is difficult to study with conventional biochemical methods.

In order to interrogate biomolecular hydrogels directly on the supramolecular level, we have developed an unconventional approach that draws on knowledge from several scientific disciplines. Exploiting surface science tools, such as supported lipid bilayers, we tailor-make model systems by directed self-assembly of purified components on solid supports. With a toolbox of surface-sensitive analytical techniques, including quartz crystal microbalance, ellipsometry, atomic force microscopy and microinterferometry, these model systems can be investigated quantitatively and in great detail. From the experimental data, combined with polymer theory, we develop a better understanding of the relationship between the supramolecular organization and dynamics of biomolecular hydrogels, their physico-chemical properties and their biological function. To illustrate this concept, I will present some of our recent work on the “sweet” jelly-like matrix that forms around the mammalian egg during ovulation (the so-called cumulus cell-oocyte complex matrix) and that is crucial for fertility, and on the proteoglycan-meshwork that contributes to the load-bearing and lubricating properties cartilage.