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 Microbes can grow on nitric oxide (NO)
18.03.2019 | Max-Planck-Institut für Marine Mikrobiologie

nachricht Novel methods for analyzing neural circuits for innate behaviors in insects
15.03.2019 | Kanazawa 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: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

Im Focus: Sensing shakes

A new way to sense earthquakes could help improve early warning systems

Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...

Im Focus: A thermo-sensor for magnetic bits

New concept for energy-efficient data processing technology

Scientists of the Department of Physics at the University of Hamburg, Germany, detected the magnetic states of atoms on a surface using only heat. The...

Im Focus: The moiré patterns of three layers change the electronic properties of graphene

Combining an atomically thin graphene and a boron nitride layer at a slightly rotated angle changes their electrical properties. Physicists at the University of Basel have now shown for the first time the combination with a third layer can result in new material properties also in a three-layer sandwich of carbon and boron nitride. This significantly increases the number of potential synthetic materials, report the researchers in the scientific journal Nano Letters.

Last year, researchers in the US caused a big stir when they showed that rotating two stacked graphene layers by a “magical” angle of 1.1 degrees turns...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Researchers measure near-perfect performance in low-cost semiconductors

18.03.2019 | Power and Electrical Engineering

Nanocrystal 'factory' could revolutionize quantum dot manufacturing

18.03.2019 | Materials Sciences

Long-distance quantum information exchange -- success at the nanoscale

18.03.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>