Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

It takes 2 to infect

30.11.2009
Structural biologists shed light on mechanism of invasion protein

Two so-called invasion proteins are crucial for infection. Each binds a specific receptor on the surface of human cells, which stimulates the host cell to take up the pathogen. Normally, these receptor molecules exert a different function, for example the regulation of cell growth and wound healing. The group's results have now been published in the current issue of the "Journal of Molecular Biology".

Spoiled meat is one of the sources for Listeria infections leading to listeriosis. Pregnant women, newborns and immune compromised people are susceptible for a severe progression of this disease. Firstly, the pathogen breaches the intestinal barrier and thus enters the body. The key for further spreading is the invasion protein internalin B that is located on the bacterial surface. On human cells, internalin B activates a receptor molecule called "Met", thereby signaling the host cell to take up the pathogen. Inside the cell, Listeria uses the host cell's nutrients and is somehow sheltered from an immune response.

Until now, the researchers did not know how the bacterial invasion protein activates the human receptor. To solve this question, the structural biologists from the HZI first analysed the crystal structures of the single internalin B molecule and of its complex bound to human Met. "In X-Ray structural analysis we noticed that in protein crystals two internalin B molecules align characteristically," says Hartmut Niemann, assistant professor at the University of Bielefeld. Professor Dirk Heinz, head of the structural biologists at the HZI, explains: "This gave rise to the idea of a dimer – two congregated internalin B molecules – playing a pivotal role in the activation of the Met receptor."

Minor changes in the internalin B molecule confirmed their hypothesis: inhibiting the congregation of two internalin B molecules prevented the activation of Met. On the other hand, strengthening the interaction resulted in particularly strong receptor activation.

These results may lead to the development of new protein drugs in the future. "Met plays a major role in the body, for example during wound healing," says Heinz. "Thanks to the extraordinary ability of the internalin B dimer to strongly activate Met, therapeutics for improved wound healing may result someday."

Originalartikel: Ligand-Mediated Dimerization of the Met Receptor Tyrosine Kinase by the Bacterial Invasion Protein InlB. Davide M. Ferraris, Ermanno Gherardi, Ying Di, Dirk W. Heinz and Hartmut H. Niemann. J Mol Biol. 2009 Nov 6. [Epub ahead of print]. doi:10.1016/j.jmb.2009.10.074

Dr. Bastian Dornbach | EurekAlert!
Further information:
http://www.helmholtz-hzi.de

More articles from Life Sciences:

nachricht Single-stranded DNA and RNA origami go live
15.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

nachricht New antbird species discovered in Peru by LSU ornithologists
15.12.2017 | Louisiana State 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: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>