Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Breakthrough: structure of membrane protein described by Hebrew University, German researchers

05.08.2005


Illustration of the membrane protein NhaA. Area outlined by the white dots indicate the funnel of the protein extending into the cell membrane.


The structure of the membrane protein NhaA has been revealed by researchers at the Hebrew University of Jerusalem and the Max Planck Institute of Germany.

Membrane protein research is at the forefront of modern biological study, with great potential consequences for development of new medicinal treatments and genetic engineering of plants.

The research on NhaA has been carried out by Etana Padan, the Adelina and Massimo DellaPergola Professor of Life Sciences, with Dr. Rimon Avraham, both of the Silberman Institute of Life Sciences at the Hebrew University, and Prof. Hartmut Michel, Nobel prize winner for chemistry in 1988, of the Max Planck for biophysics in Frankfurt, Germany. Their work, described in a recent edition of the journal Nature, was supported by a grant from the German-Israel Binational Science Foundation;



Proteins such as NhaA are found in the membranes of every living cell, from bacteria and up to humans. Until now, the structure of fewer than 50 cell membrane proteins have been discovered, as opposed to 30,000 soluble proteins.

“The location of the proteins in the cell membranes presents tremendous difficulties in research,” said Prof. Padan. “Unlike the majority of those proteins which are soluble in water, the membrane proteins are soluble only in fats or in the presence of detergents.”

The cell membrane is the crossroads of busy, two-way “traffic” through which materials and impulses travel into and out of the cell. The fatty cell membrane is impenetrable to most of these materials and signals; and it is therefore the proteins within the membranes that are responsible for the communication between the cell and its environment. Indeed, more than 60 percent of the medicines in use today are directed at the cell membrane proteins. Since the cell membrane proteins are exposed, in part, to areas extending outside the cells, the medicines are able to reach them without entering the cell itself.

In Prof. Padan’s laboratory, the researchers succeeded in isolating the gene that encodes NhaA in bacteria and in producing a large quantity of the protein in its active state. This achievement paved the way for determining the structure of the protein, providing an essential insight into its mechanism of activity and regulation. NhaA protects the volume of the cell and its internal, normative state in terms of its salinity and acidity.

The deciphering of the NhaA protein’s structure was done utilizing three-dimensional crystals of the protein which diffract x-rays. The work of analyzing the diffraction was done using the powerful electron accelerators in Grenoble, France, and Zurich, Switzerland.

“In this way we were able to reveal the wonderful architecture of the membrane protein, which was unknown before,” said Prof. Padan. “In the center of the protein we found a wide funnel which extends into the cell. The funnel narrows and ends at the point at which it binds with the sodium or the hydrogen deep within the cell membrane. Near that point two chains of the protein unite into a unique structure.”

The researchers believe that this unique structure is the basis for the activity of the protein. The protein operates as a kind of pump, utilizing energy which it receives from processes taking place within the cell. The protein structure thus acts as a kind of molecular motor. This “motor” is connected to the area found at the mouth of the funnel that apparently conveys signals to “modulate” the motor according to the acidity within the cell. The result is that the protein’s activity is controlled in accordance with the needs of the cell in relation to its acidic and basic levels.

Jerry Barach | alfa
Further information:
http://www.huji.ac.il

More articles from Life Sciences:

nachricht Cryo-electron microscopy achieves unprecedented resolution using new computational methods
24.03.2017 | DOE/Lawrence Berkeley National Laboratory

nachricht How cheetahs stay fit and healthy
24.03.2017 | Forschungsverbund Berlin e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>