Water is no passive spectator of biological processes; it is an active participant. Protein folding is thus a self-organized process in which the actions of the solvent play a key role.
So far, the emphasis in studies of protein folding processes has been on observation of the protein backbone and its side chains. Researchers led by Martin Gruebele and Martina Havenith have now been able to detect changes in the protein–water network during protein folding in real time.
As they report in the journal Angewandte Chemie, this team of scientists at the University of Illinois (Urbana, USA) and the Ruhr University in Bochum (Germany) used a spectroscopic technique called KITA (kinetic terahertz absorption) to make their observations.
Terahertz (THz) radiation consists of electromagnetic waves in the submillimeter range, putting it between the infrared and microwave ranges. Efficient sources of THz radiation are now available, making it possible to directly measure the absorption of biomolecules in aqueous buffers on the picosecond time scale. Both the skeletal movements of proteins and the collective motions of water molecules surrounding proteins occur on this time scale. The research team recently demonstrated that THz-range absorption spectroscopy is a sensitive method for the investigation of the water shell that surrounds proteins. In the layers immediately surrounding the protein, the water molecules are networked to each other differently than in pure water. Their absorption of THz radiation at certain frequencies is thus changed.
The way in which a protein folds to a very large extent determines its function. The folding process is very fast. The movements of the protein backbone influence the solvent, and the dynamics of the solvent can in turn influence the dynamics of the protein—thus playing an important role in the folding process. Kinetic THz absorption (KITA) registers the damping and phase-shifting of an electrical THz field caused by the folding of a protein. Comparison with results obtained by other methods confirms that KITA detects reorientations of the interactions between a protein and its water shell in an early phase of the folding process.
Author: Martin Gruebele, University of Illinois, Urbana (USA), http://www.scs.uiuc.edu/%7Emgweb/
Title: Real-Time Detection of Protein–Water Dynamics upon Protein Folding by Terahertz Absorption Spectroscopy
Angewandte Chemie International Edition 2008, 47, No. 34, 6486–6489, doi: 10.1002/anie.200802281
Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences
Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller University
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.
When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...
At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.
Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...
16.03.2018 | Event News
13.03.2018 | Event News
08.03.2018 | Event News
16.03.2018 | Earth Sciences
16.03.2018 | Physics and Astronomy
16.03.2018 | Life Sciences