EU grants €2.5 million for terahertz probe into protein reactions

Team led by Bochum's Martina Havenith develops new method to measure real time heat and energy changes at protein-solvent interface.

Prof Dr Martina Havenith from the Ruhr-Universität Bochum (RUB) http://optics.org/news/7/4/25 The European Research Council(ERC) is to finance a research team led by Prof Dr Martina Havenith from the Ruhr-Universität Bochum (RUB) with €2.5 million over five years to develop an optical procedure to investigate the behavior of proteins in biochemical reactions. In a process called time-resolved terahertz calorimetry, the RUB scientists say they will “tinker with terahertz laser spectroscopy to deduce with nanosecond precision how proteins and solvent exchange energy and rearrange themselves in biological processes”. Professor Havenith, who is Chair of the Department of Physical Chemistry II at RUB and speaker for the cluster of known as European Research Council (“Resolv”), will lead an international team with Prof Dr Irit Sagi from the Weizmann-Institute in Israel and Dr Matthias Heyden from the Max-Planck-Institute for Coal Research in Mülheim at the Ruhr, Germany. ’Underestimated role of water’ Fundamental biological processes such as protein folding, protein-protein interactions and enzymatic reactions take place in watery solutions and depend upon the ability of the reacting molecules to recognize themselves in a solvent. Molecular recognition is mediated through various chemical interactions that can be studied by calorimetry, measuring enthalpy, entropy d other associated energetic parameters. Unfortunately, current calorimetric approaches are all based on heat transfer, hence they deliver results on time scales of 1 to 100 seconds and can analyze the system only at equilibrium, that is when molecules are already bound. However, as Havenith points out, a successful reaction is the result of a dynamic interplay between the partner molecules and the solvent. "Terahertz-Calorimetry promises to investigate these processes, for the first time in real time with a million time better time resolution," the scientists claim. The new technique will use terahertz light sources to excite solvent molecules and biomolecules at the time scales of hydrogen bond dynamics in water as well as large-amplitude motions of proteins and nucleic acids. “If we are able to collect full information on these time-scale dynamics, we can deduce useful values of entropy, enthalpy, and so on associated with molecular recognition processes”, said Havenith. Time-resolved terehaertz calorimetry will also offer, the opportunity to directly access the distinct contributions of the solute entropy changes versus those of the solvent. To this end, the Bochum-based project will combine the expertise gathered in terahertz laser development with microwave technology, biophysics, calorimetry and theoretical modeling. “Interdisciplinary discussions within Resolv were crucial to inspire us the THz calorimetry idea”, added Havenith. Two grants In the latest application round for the ERC's Advanced Grants, two further researchers from the Ruhr-Universität Bochum have been successful: IT security expert Prof Dr Christof Paar also raised such a grant. Via these two projects, the RUB will receive up €5 million in total. The European Union launched the European Research Council in 2007 to fund excellent research in Europe. The ERC Advanced Grants program targets senior researchers with ground-breaking ideas that may be risky to pursue, awarding up to €2.5 million for five years. The 2015 call received almost 2000 project applications from 29 countries, but only about 14% of them were selected after a peer review process. “I received the confirmation message at Zürich airport after an 11-hour flight. I had to read it three times before I believed it. It is such a great chance to test some exciting new ideas”, said Havenith.

Observed 'live': Water is an active team player for enzymes

Water acts as an 'adhesive' in biological enzyme substrate compounds

http://www.eurekalert.org/pub_releases/2011-09/rb-ow091911.php

In biologically active enzyme substrate compounds, as can be found in medicines, water plays a more decisive role than has been imagined up to now. The surrounding water acts like an "adhesive", in order to keep the substrate at the right place on an enzyme. For this, the dynamism of the water is retarded. Scientists at the RUB under Prof. Dr. Martina Havenith (Physical Chemistry) in close cooperation with the group of Prof. Irit Sagi from the Israeli Weizmann Institute have been able to observe and prove the retardation of the water's dynamism "live" for the first time in close. The researchers are reporting on their results in Nature Structural & Molecular Biology.
Which role does the solvent play?Enzymes are natural substances accelerating and controlling the metabolic processes in the body. They are, for example, of central importance for the immune system, as they control the balance between activating and inhibiting defensive reactions and play an important role in inflammation reactions. It had been known for some time that enzymatic functions take place in various solvents at highly differing speeds. But up to now, the contribution made by the solvent - this is water in biological processes - on a molecular level had not yet been clarified.
Two new techniques combinedProf. Havenith's group at the RUB and Prof. Irit Sagi's group at the Institute of Structural Biology of the Weizmann Institute have combined two newly developed experimental techniques, in order directly to prove the significance of the water for the enzymatic functions. The object of their study was matrix metalloproteases (MMP). MMPs can be found outside our cells in the so-called extracellular matrix, where they fulfil central tasks as message transmitters, managers or maintenance units on a molecular level. As a result of the decomposition of the extracellular matrix, the MMP are actively and directly involved in the reconstruction of our tissue, e.g. in embryo or tumour growth and in wound healing. The numerous possible fields of use make this family of enzymes an important field of study for the development of medicines. "The mechanism for the enzymatic activity of the matrix metalloproteases is however not yet known on a molecular level, which poses still challenges on any synthetic drug design," says Prof. Havenith.
Precise characterisation of all "players"For precise understanding of the reaction, the researchers looked at all the "players" involved: the matrix metalloprotease enzyme as the "lock", its activating substrate - the "key" - and the water as a solvent, the reaction environment. In the experiment, the scientists investigated the binding of the substrate to the MMP. With the help of time-resolved X-ray spectroscopy, they were able to characterise precisely the structural changes in the vicinity of the active enzyme centre (here: of the zinc atom) with atomic resolution. With the help of kinetic THz absorption spectroscopy (KITA), they recorded the changes in time of the fast water movements.
The role of water for future drug designIn various MMP-protein combinations, an unambiguous correlation was found between the fluctuations of the water network, the structure changes and the function. Molecular dynamic simulations provided an explanation for the observations: While the substrate has not found yet the "correct point" of the enzyme - the lock-, the water dynamism, i.e. the opening and reformation of hydrogen bonds between water molecules (the "terahertz dance" of the water), is fast. At the same time as the substrate is docking onto the active centre, the water movement in the environment slows down. Water then acts then more like a kind of adhesive there, which keeps the substrate at this point. This change of the THz dance of the water with the formation of the enzyme-substrate binding is however exclusively observed in biologically active enzyme-substrate combinations. "The retardation of the water dynamism, observed for the first time, thus appears to be an essential part of the functional control", says Prof. Havenith. "Therefore, in future, taking the role of the water into account in the development of medicines, for example for tumour therapy, might become important."
"Solvation Science@RUB"This work is part of "Solvation Science@RUB", the research topic of the new center of molecular spectroscopy and simulation of solvent controlled processes at the RUB (ZEMOS), and of the excellence cluster application of the RUB "RESOLV", which is now under review at the German council of science. In chemistry, process engineering and biology, there are an enormous number of publications describing solvents as inert (passive) media for molecular processes. Beyond this traditional view, the active role of the solvent is however becoming more and more visible. New experimental and theoretical methods now permit investigation, description and systematic control of the structure, dynamism and kinetics of complex solvation phenomena on a molecular level. "So it is now most timely to develop general models with a predictive power for solvation processes", says Prof. Havenith. Precisely that is the objective of "Solvation Science@RUB".

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TitleM. Grossman, B. Born, M. Heyden, D. Tworowski, G. Fields, I. Sagi, M. Havenith: Correlated structural kinetics and retarded solvent dynamics at the metalloprotease active site. Nature Structural & Molecular Biology, Advance Online Publication (AOP), doi: 10.1038/nsmb.2120
http://www.nature.com/nsmb/journal/vaop/ncurrent/abs/nsmb.2120.html
Further informationProf. Dr. Martina Havenith, Faculty of Chemistry and Biochemistry of the Ruhr-Universität Bochum, Chair of Physical Chemistry II, Tel. 0234/32-24249, martina.havenith@rub.de
Editorial: Jens Wylkop

Prior related link:
http://terahertztechnology.blogspot.com/2011/05/water-and-biological-molecules-probed.html