Structure and dynamics of soft and biological materials. I & II

Research Project, 2012 – 2019

This project proposal is a continuation of a project that has been funded by VR since 1999. Although the scientific issues have changed over the years it has considered water in soft and biological materials, with a particular focus in recent years on understanding the role of water for biomolecular dynamics and functions. Here, we ask for a four years continuation of this project, with the ultimate goal to understand the role of water for life.

It is well known that life, as we know it, would not exist without water. However, despite this fact, most scientific studies of biomaterials neglect this essential influence of the associated water and therefore it is only poorly understood how and why water is of such importance for life. The purpose of this proposal is to consider this issue and try to understand how and why water affects the properties of different biological systems, such as proteins, lipid membranes and DNA. Furthermore, since the unique role of water can only be understood by elucidating how the properties of biological materials change in a non-aqueous environment, such as a cryoprotectant, it is evident that the here proposed studies of biomolecules in such environments are also highly relevant for understanding cryopreservation of biological materials. The use of cryopreservation for the conservation of basically all types of biological materials has become a rapidly growing technique in recent years, mainly because of the possibilities to store stem cells, embryos and whole body organs for future uses. The cryopreservation of food and pharmaceuticals is also a multibillion business, where improved techniques of preservations can save large amounts of money for this industry. Hence, a deeper understanding of the role of water and other solvents in biological materials will have an important impact on industrial and medical applications, as well as on the basic understanding of the principles of life.

The aim of this project is that the following specific goals should be reached:

• (a) Understand how and why water affects the properties of different types of biomolecules.
• (b) Understand how ice formation and different types of relaxation processes affect cryopreservation.

Since we will mainly investigate the relatively slow relaxational dynamics of biomolecules and their associated solvent, the studies will mainly be based on dielectric spectroscopy and quasielastic neutron scattering, which allow us to cover all dynamics on a broad time range from 1 ps to 1000 s. However, we will also use differential scanning calorimetry (DSC) to characterise the samples as well as investigate specific temperature induced events in the samples, such as e.g. protein denaturation and the protein glass transition. To obtain structural information and to reach more detailed understanding of the solvent–biomolecule interactions we also aim to use small- and wide-angle neutron diffraction, Raman and IR absorption spectroscopy and also molecular dynamics (MD) simulations in collaboration with Prof. Michael Vogel at Technical University Darmstadt. To relate the dynamics we observe for proteins to their biological activities we will also perform such activity measurements in collaboration with other scientists.