Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Peptides as tags in fluorescence microscopy

30.11.2016

Advance in biomedical imaging: The Biocenter of the University of Würzburg in close collaboration with the University of Copenhagen has developed an alternative approach to fluorescent tagging of proteins. The new probes are practicable and compatible with high-resolution microscopic procedures.

Fluorescence microscopy visualizes the molecular elements of cells. Proteins of nerve cells, for instance, can be labelled using probes which are subsequently excited with light to fluoresce. In the end, the fluorescence signal is used to generate microscopic images of the real position, arrangement and number of proteins.


Synapses of brain cells made visible using fluorescence tagging based on antibodies: pre-synapses (red) and post-synapses (green) appear out of focus; the synaptic cleft is not fully resolved.

(Picture: Franziska Neubert & Sören Doose)


Pre-synapses are tagged with antibodies (red); the post-synapses are labelled with peptides which clearly enhance resolution. Post-synapses and synapses are shown in a resolution of about 130 nm.

(Picture: Franziska Neubert & Sören Doose)

"It is very difficult to tag the protein in question effectively and specifically," says Professor Markus Sauer from the Chair of Biotechnology and Biophysics of the Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany. Antibodies are often used for this purpose, because they attach firmly and selectively to proteins. "However, this approach returns relatively blurred images, as the antibodies themselves are large proteins."

Previous methods hardly practicable

The drawbacks of antibodies become apparent in neurobiological research – for example when trying to understand the functioning of the brain and the neurons at the molecular level.

Several attempts have been made to visualize the post-synaptic scaffold protein gephyrin using improved tags. "So far, however, the approaches have shown little practical benefit, because they either required genetic manipulation of the cells or were based on antibodies which impair the image resolution due to their size," Sauer explains.

Alternative strategy implemented

To make progress in this field of research, Sauer's JMU research group teamed up with the University of Copenhagen (Denmark) to pursue an alternative strategy, namely to develop peptide probes. These probes should be much smaller than antibodies but attach to their target proteins with comparable efficiency. The results have been published in the journal "Nature Chemical Biology".

"We have established a technology platform here in Copenhagen which allows us to simultaneously visualize and test a great variety of modified peptides in the size of a microchip. This made it easy for us to design a specific peptide for gephyrin" says Professor Hans Maric from the Center for Biopharmaceuticals. For the peptide to work efficiently as a probe, it was equipped with two other functions: One makes it more membrane permeable, the other imparts fluorescence.

New possibilities opened up

So far, the research team at the University of Würzburg has used the new probes mainly to verify the feasibility of the new approach. The team is pleased with the results: "We believe that it is possible now to develop similar probes for other key proteins," Sauer further.

The JMU professor outlines the possibilities enabled by the new development: "Probes that are highly specific, attach effectively and above all are small hold great potential. They can help shed light on the layout of proteins in their natural cellular context and even allow quantifying them."

Maric, H. M., Hausrat, T. J., Neubert, F., Dalby, N.O., Doose S., Sauer M., Kneussel M., Strømgaard K. Gephyrin-Binding Peptides Visualize Post-Synaptic Sites and Modulate Neurotransmission, Nature Chemical Biology, 28. November 2016. DOI: 10.1038/nchembio.2246

Contact

Prof. Dr. Markus Sauer, Chair of Biotechnology and Biophysics, University of Würzburg, T +49 931 31-88687, m.sauer@uni-wuerzburg.de

Prof. Dr. Hans Maric, Center for Biopharmaceuticals, University of Copenhagen, T (0157) 34390860, HansMichael.Maric@sund.ku.dk

Robert Emmerich | Julius-Maximilians-Universität Würzburg
Further information:
http://www.uni-wuerzburg.de

More articles from Life Sciences:

nachricht Bacteria as pacemaker for the intestine
22.11.2017 | Christian-Albrechts-Universität zu Kiel

nachricht Researchers identify how bacterium survives in oxygen-poor environments
22.11.2017 | Columbia University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>