Navigation Links
Specialised germanium surface as universal protein adapter
Date:3/8/2013

Researchers at the Ruhr Universitt Bochum have developed a new method for attaching proteins to the surface of germanium crystals for the first time also membrane proteins. This enables time-resolved tracking of the interactions between molecules using infrared spectroscopy in a way that is accurate down to atomic resolution. The method is applied in the EU project "Kinetics for Drug Discovery, K4DD", in which scientists explore the interplay of drugs and their interaction partners. With the new technology, the researchers can also study so-called G-protein-coupled receptors, which are the site of action for many drugs. The team of Prof. Dr. Klaus Gerwert, PD Dr. Carsten Ktting and Jonas Schartner from the Chair of Biophysics reports in the "Journal of the American Chemical Society".

Attaching proteins to germanium using electron pair bonds

Using infrared (IR) difference spectroscopy, researchers analyse dynamic processes in proteins. In an earlier study, Bochum's biophysicists already succeeded in binding proteins to germanium surfaces using lipids, thus making them accessible to IR spectroscopy (as reported in September 2012: http://aktuell.ruhr-uni-bochum.de/pm2012/pm00284.html.de). For this, the researchers shine infrared light into the germanium crystal, which is multiply reflected at its boundary surfaces. Part of the light leaves the crystal and thus reaches the proteins bound to the surface. Previously, the researchers used hydrophilic interactions between the crystal and lipid i.e. interactions between polar groups of the molecules for the bonding. Now they coupled the proteins via an electron pair bond to the germanium. This kind of bond is more stable and works both for soluble and membrane proteins. "Membrane proteins need a kind of soap as an outer shell, a detergent, which washes off a lipid layer. In contrast, our newly developed surface remains stable", Jonas Schartner says.

Chemical modular system

As in a modular system, the researchers placed various molecular layers, one above the other, on the germanium crystal. First, they produced hydroxyl groups on the germanium surface, each consisting of an oxygen atom and a hydrogen atom. The product is referred to as activated germanium. The next layer was formed by a new kind of triethoxysilanes, a hydrocarbon compound, which the RUB team produced itself. The researchers anchored one end of the triethoxysilanes covalently to the germanium, i.e. via an electron-pair bond. They converted the other end into a protein trap. All the proteins that carry a particular adapter, the His-tag, can be attached to this. "There are already a lot of proteins available with this universal adapter" Carsten Ktting says.

Modifying the germanium surface in a controlled manner

Using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy (XPS), the researchers kept track of what happened when stacking the different layers on the germanium crystal. Together with Prof. Dr. Martin Muhler and Bastian Mei from the Laboratory of Industrial Chemistry, the biophysicists were able to accurately determine the atomic composition of the layers with the XPS. Proteins can also be observed on surfaces using other techniques, such as surface plasmon resonance. "With surface plasmon resonance, the gradual modification of the surface is carried out blindly," Jonas Schartner says. "We've observed each modification step live and thus have very good control over the process."

Functional test for the new process successful

A test confirmed that the newly created surface serves its purpose. The researchers equipped the germanium crystal with the switch protein Ras, which plays an important role in carcinogenesis. There they allowed it to interact with a second molecule that switches Ras on and off. These two states "on" and "off" - were reflected in the infrared difference spectra. With the new method, the RUB team thus successfully made a protein interaction visible. In future, drugs and their receptors are to be put to the test. "Using the conventional surface plasmon resonance method, it is only possible to determine whether an interaction takes place. A special feature of our method is that different types of active substance interactions also lead to differences in the difference spectrum", Jrn Gldenhaupt says. "With this additional information, the mechanism of action can be examined much better. This can be critical in the development of active substances."


'/>"/>

Contact: Dr. Carsten Ktting
carsten.koetting@rub.de
49-234-322-4873
Ruhr-University Bochum
Source:Eurekalert

Related biology news :

1. Mutation altering stability of surface molecule in acid enables H5N1 infection of mammals
2. A cooler way to protect silicon surfaces
3. Discovering cell surface proteins behavior
4. Stem cell breakthrough could lead to new bone repair therapies on nanoscale surfaces
5. How the tilt of a cell-surface receptor prevents cancer
6. Numerical study suggests subsea injection of chemicals didnt prevent oil from rising to sea surface
7. Illuminating the no-mans land of waters surface
8. Surface analysis techniques for advanced materials enhance Mazovias research potential
9. Ancient microbes found living beneath the icy surface of Antarctic lake
10. 3dMD Transitions Anatomical Research from 3D-Static to 4D-Movement Surface Imaging
11. Professor publishes on first-ever imaging of cells growing on spherical surfaces
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/3/2017)... 2017  Data captured by IsoCode, IsoPlexis ... a statistically significant association between the potency ... and objective response of cancer patients post-treatment. ... whether cancer patients will respond to CAR-T ... as to improve both pre-infusion potency testing and ...
(Date:3/30/2017)... KONG , March 30, 2017 The ... a system for three-dimensional (3D) fingerprint identification by adopting ground breaking ... into a new realm of speed and accuracy for use in ... at an affordable cost. ... ...
(Date:3/29/2017)... , March 29, 2017  higi, the health ... in North America , today announced ... and the acquisition of EveryMove. The new investment and ... set of tools to transform population health activities through ... lifestyle data. higi collects and secures data ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... 11, 2017 , ... The CRISPR-Cas9 system has ... and avoiding the use of exogenous expression plasmids. The simplicity of programming this ... gain-of-function studies. , This complement to loss-of-function studies, such as with RNAi ...
(Date:10/11/2017)... Netherlands and LAGUNA HILLS, Calif. ... Institute of Cancer Research, London (ICR) ... MMprofiler™ with SKY92, SkylineDx,s prognostic tool to risk-stratify patients with ... known as MUK nine . The University of ... which is partly funded by Myeloma UK, and ICR will ...
(Date:10/10/2017)... Angeles, CA (PRWEB) , ... ... ... Inc., a development-stage cancer-focused pharmaceutical company advancing targeted antibody-drug conjugate (ADC) therapeutics, ... uses of targeted HPLN (Hybrid Polymerized Liposomal Nanoparticle), a technology developed in ...
(Date:10/10/2017)... ... October 10, 2017 , ... ... process optimization firm for the life sciences and healthcare industries, announces a presentation ... San Francisco. , The presentation, “Automating GxP Validation for Agile Cloud Platforms,” will ...
Breaking Biology Technology: