Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Infrared spectroscopy: Interaction between proteins and pharmaceuticals in atomic detail

03.09.2012
Anchored proteins
RUB-Biophysicists use surface-sensitive spectroscopy

RUB-Researchers from the Chair for Biophysics have developed a new method for the detailed study of the interaction between pharmaceuticals and their target proteins.

The pharmaceutical industry has already taken notice of the new infrared spectroscopy technique; the method is supposed to be implemented to investigate pharmacological agent-protein interactions in the EU project K4DD, which is supported by various major European pharmaceutical companies. “We now have a tool in our hands with which we can research the dynamics of pharmacologically interesting proteins in atomic detail,” Prof. Dr. Klaus Gerwert said.

“We want to undertake a targeted screening of substance libraries to look for potential pharmacological agents.” PD Dr. Carsten Kötting added that “with our technique future pharmaceuticals can be more closely tailored to illness-causing proteins, which can noticeably reduce the negative side effects of these drugs.” They described the new method together with Dr. Jörn Güldenhaupt and Philipp Pinkerneil in the scientific journal “ChemPhysChem,” which dedicated its cover story to this topic.

The new method: from three to one

With infrared difference spectroscopy, researchers follow dynamic processes in proteins. For a long time, these processes could only be observed in light-activated proteins, but not in proteins that are activated by binding with ligands – but this is usually how many illness relevant molecules are activated. To analyze the dynamics of such proteins, researchers have to fasten them to the measurement surface and pour a pharmacological-substance over them; the proteins can then interact with and be activated by this substance. Even though this binding technique is possible, it cannot be used for all proteins. The RUB-Team worked around this problem by combining infrared (IR) spectroscopy with a surface-sensitive technique (attenuated total reflectance) and so-called “His-Tagging” (anchoring proteins to the measurement surface).

Attenuated total reflectance: bringing the infrared beam to all proteins

In conventional IR spectroscopy, an infrared beam is passed through a liquid sample; part of the light is absorbed by the proteins, which allows researchers to draw conclusions about their structure. The RUB-researchers beamed the infrared light through a germanium crystal, on whose surface proteins were anchored. At the boundaries of the crystal the light is reflected over and over, thereby spreading throughout the crystal (attenuated total reflectance). During this process, some of the light waves leave the crystal and reach the proteins that are fastened to its surface. A similar technique, the Surface Plasmon Resonance, is the standard for use in the pharmaceutical industry, but does not have the atomic resolution capabilities of the new technique.
Part of the chain: the His-Tag

This bonding of the proteins to the crystal succeeds through usage of the His-Tag, a simple amino acid chain, which is commonly attached to proteins today to enable their biochemical study – it is essentially a universal adapter. Through the His-Tag the RUB-researchers were able to anchor the protein to the germanium crystal. As a result the molecules were firmly bound to the measurement surface, which transmits the infrared light to the proteins by the process of attenuated total reflectance. The big advantage: an abundance of proteins are already fitted with the His-Tag; therefore examining them with the new method is unproblematic. All other proteins to which a His-Tag is attached can now also be accessed by IR spectroscopy. “This will help answer a multitude of biological and medical questions,” Gerwert said.

Establishment of the new method with the switch protein Ras
The RUB-Team first tried their new method on the switch protein Ras, the central on/off switch for cell growth. Defect, or oncogenic Ras, is one of the cells most frequently responsible for causing cancer. The researchers succeeded in fastening Ras to the measurement surface with the His-Tag, and then activating the Ras by binding it to a ligand. “The technique is so sensitive that we could resolve the signal of a five nanometer thick protein layer. That’s about 1/10000 of the diameter of a human hair,” RUB-researcher Dr. Jörn Güldenhaupt, who contributed significantly to the development of the new method, said. Even the smallest structural changes during the Ras protein’s switch from its “on” to its “off” state were recognized with the “protein-nanoscope.”

Project funding

Funding for the project came from the Protein Research Department at the RUB, from the state of NRW in the framework of the Center for Vibrational Microscopy (CVM) and from the SFB 642, “GTP and ATP Dependent Membrane Processes,” whose speaker is Prof. Gerwert.

Bibliographic record

P. Pinkerneil, J. Güldenhaupt, K. Gerwert, C. Kötting (2012): Surface-attached polyhistidine-tag proteins characterized by FTIR difference spectroscopy, ChemPhysChem, doi: 10.1002/cphc.201200358

Figrue online

A figure illustrating the new method can be downloaded from the following website:

http://aktuell.ruhr-uni-bochum.de/pm2012/pm00284.html.en

Further Information

Prof. Dr. Klaus Gerwert, Chair for Biophysics, Faculty for Biology and Biotechnology at the Ruhr-Universität, 44780 Bochum, Germany, Phone: +49/234/32-24461

klaus.gerwert@bph.ruhr-uni-bochum.de

Click for more

Biophysics at RUB
http://www.bph.ruhr-uni-bochum.de/index_en.htm

Full text article
http://onlinelibrary.wiley.com/doi/10.1002/cphc.201200358/full

Editorial Journalists: Charlotte Ziob/Julia Weiler

Dr. Josef König | idw
Further information:
http://www.ruhr-uni-bochum.de

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>