Reedijk Symposium 2016: Guest lecturers: Prof. Martina Havenith & Prof. Sijbren Otto

Published on September 22, 2016
Reedijk Symposium 2016: Guest lecturers: Prof. Martina Havenith & Prof. Sijbren Otto

On Friday the 28th of October the seventh annual Reedijk Symposium will be held. During this day lectures will be given by several of our colleagues and two external guest speakers: "Solvation Science - THz spectroscopy provides new answers to an old topic" by Prof. dr. Martina Havenith (Ruhr-Universität Bochum), and "Can we make life in the lab?" by Prof. dr. Sijbren Otto (RUG).

The presentations will cover the breadth of the chemistry research performed in our institute. Poster presentations by PhD students are also part of the programme.

The complete programme of the day can be found here.

Prof. dr. Martina Havenith: Solvation Science – THz spectroscopy provides new answers to an old topic

The majority of chemical reactions – among those many that are central to important industrial processes – and virtually all biological processes, take place in a liquid-state environment. Solvents– with water being the most prominent – are used to “solvate” molecular species from reagents to proteins and thereby transfer these as “solutes” into the liquid state. Understanding “the role of water in the myriad of processes – from catalysis to molecular recognition “was addressed as one of the main challenges for chemistry in next century. Now, we witness the emergence of Solvation Science as a new interdisciplinary field to understand the influence of solvation on reactions, the function of biomolecules, and processes at liquid-solid interfaces.

Water’s flexible network enables it to adapt its structure and dynamics. Hydration water makes significant contributions to the structure and energy of proteins and provides a responsive surrounding which allows for conformational changes. In particular, water may hold the key to the way proteins interact, fold, bind substrates, and aggregate. Water at protein interfaces (hydration water or interfacial water) has been shown to thermodynamically stabilize the native structure of bio-macromolecules, to affect protein flexibility, and to contribute to molecular recognition in enzyme catalysis. Protein-water interactions are now known to shape the “free energy folding funnel” that drives protein folding.

We could show that THz absorption spectroscopy is a powerful tool to probe hydration dynamics of biomolecules. Under ambient, physiologically relevant conditions 90% of the modes which contribute to the total entropy of the solvated protein are captured by the low frequency modes of the protein/solvent, i.e. the vibrational density of states (VDOS) between 0 and 10THz (300cm-1). I will present examples for low frequency spectra of hydration water around solutes and explain how these provide sensitive probes of hydration dynamics. THz calorimetry will be introduced as a new tool for water mapping, i.e. gives access to spatially resolved values of ΔCp, ΔS, ΔH and ΔG Transient THz spectroscopy can be used to record snapshots of the low frequency spectrum of a solvated proteins subsequent to initiation of the protein folding, thus capturing changes during hydrophobic collapse. We propose that water is not just a passive spectator solvent in biological processes, but has a vital function in most biomolecular and cellular processes.

Prof. dr. Sijbren Otto: Can we make life in the lab?

How the immense complexity of living organisms has arisen is one of the most intriguing questions in contemporary science.

We have started to explore experimentally how organization and function can emerge from complex molecular networks in aqueous solution. We focus on networks of molecules that can interconvert, to give mixtures that can change their composition in response to external or internal stimuli. Molecular recognition between molecules in such mixtures leads to their mutual stabilization, which drives the synthesis of more of the privileged structures.

As the assembly process drives the synthesis of the very molecules that assemble, the resulting materials can be considered to be self-synthesizing. Intriguingly, in this process the assembling molecules are replicating themselves, where replication is driven by self-recognition of these molecules in the dynamic network. The selection rules that dictate which (if any) replicator will emerge from such networks are starting to become clear.

We have observed that factors such as mechanical energy and the presence of cosolvents can determine which replicator wins the competition for building blocks. We have also witnessed spontaneous differentiation (a process akin to speciation as it occurs in biology) in a system made from a mixture of two building blocks. When such systems are operated under far-from-equilibrium flow conditions adaptation of the replicators to a changing environment can occur. Thus, the prospect of Darwinian evolution of purely synthetic molecules is tantalizingly close and the prospect of synthesizing life de-novo is becoming increasingly realistic.

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