Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tracked step for step: ATP splitting in membrane protein dynamically measured for the first time

11.07.2012
Tracked step for step
ATP splitting in membrane protein dynamically measured for the first time
RUB researchers report in the Journal of Biological Chemistry

How a transport protein obtains its driving force from the energy storage molecule ATP, has been tracked dynamically by RUB researchers. Using time-resolved infrared spectroscopy, they measured the structural changes in the bacterial membrane protein MsbA and its interaction partner ATP.


ATP splitting: The transport protein MsbA (grey) splits ATP (coloured), to generate energy for the transport process. ATP has three phosphate groups (orange-red). If one of them is split off (yellow), energy is released. The splitting process can be tracked in the infrared spectrum (above), in which the various ATP intermediate products leave characteristic bands (red: ATP, yellow: split-off phosphate, white: protein).
Image: Falk Syberg

The researchers led by Prof. Dr. Eckhard Hofmann and Prof. Dr. Klaus Gerwert from the Biophysics Department report on the results in the current issue of the Journal of Biological Chemistry.

Transport proteins are associated with various diseases

ABC transporters are membrane proteins that transport various substances from one side of the cell membrane to the other. The driving force for this is provided by the molecule ATP, a universal energy storage of the cells. ATP has three phosphate groups. If one of these splits off, energy is released. The transporters are of great medical significance as they play a central role in the multi-drug resistance of cancer cells to chemotherapeutic substances and are associated with various inherited diseases like cystic fibrosis.
In recent years, researchers have uncovered the 3D structures of several of these transporters at the atomic level. Although the architecture of the nanomachines is known, a detailed understanding of how the splitting of the energy carrier ATP dynamically enables the transport of various substances across biological membranes has so far been lacking.

Protein controls ATP splitting

The Bochum researchers have now dynamically tracked the ATP splitting, called hydrolysis, for the first time in the fat transporter MsbA from the bacterium Escherichia coli. Using fourier transform infrared spectroscopy, they studied the motor domains of MsbA, i.e. the part of the protein where the ATP splitting takes place. Using this method, researchers can track minute changes in the protein in the range of nanoseconds. Simultaneously, the method also records changes in the molecules the protein interacts with - in this case ATP.

Phosphate signals reveal what happens during the splitting

The big challenge presented by the data analysis is to assign the signals in the measured spectrum to specific molecules or molecular groups. If this is successful, you can see which groups of molecules are structurally changed and when. The biophysicists marked the phosphate groups of the ATP molecule, so that they left characteristic signals in the spectrum. In this way they tracked, how ATP bound to the transport protein, how one of its three phosphate groups split off and was released into the environment without first latching back on to the protein. “Our data also provides important clues as to how the protein moves during ATP hydrolysis. This lays the foundation for the study of the whole membrane protein, which we are going to tackle next”, says Professor Hofmann. The investigations were supported by the Protein Research Department at the RUB and funds of the collaborative research centre SFB 642 “GTP and ATP dependent membrane processes”, whose speaker is Prof. Dr. Klaus Gerwert.

Bibliographic record

F. Syberg, Y. Suveyzdis, C. Kötting, K. Gerwert, E. Hofmann (2012): Time-resolved fourier transform infrared spectroscopy of the nucleotide-binding domain from the ATP-binding cassette transporter MsbA. ATP Hydrolysis is the rate-limiting step in the catalytic cycle, Journal of Biological Chemistry, doi: 10.1074/jbc.M112.359208

Further information

Prof. Dr. Eckhard Hofmann, Protein Crystallography, Faculty of Biology and Biotechnology at the Ruhr-Universität, 44780 Bochum, Germany, tel. +49/234/32-24463, eckhard.hofmann@bph.rub.de

Click for more

Biophysics at the RUB
http://www.bph.ruhr-uni-bochum.de/index_en.htm

Editor: Dr. Julia Weiler

Dr. Josef König | idw
Further information:
http://www.ruhr-uni-bochum.de

More articles from Life Sciences:

nachricht How a mutation on the novel coronavirus has come to dominate the globe
06.07.2020 | La Jolla Institute for Immunology

nachricht Order from noise: how randomness and collective dynamics define a stem cell
06.07.2020 | Institute of Science and Technology Austria

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electrons in the fast lane

Solar cells based on perovskite compounds could soon make electricity generation from sunlight even more efficient and cheaper. The laboratory efficiency of these perovskite solar cells already exceeds that of the well-known silicon solar cells. An international team led by Stefan Weber from the Max Planck Institute for Polymer Research (MPI-P) in Mainz has found microscopic structures in perovskite crystals that can guide the charge transport in the solar cell. Clever alignment of these "electron highways" could make perovskite solar cells even more powerful.

Solar cells convert sunlight into electricity. During this process, the electrons of the material inside the cell absorb the energy of the light....

Im Focus: The lightest electromagnetic shielding material in the world

Empa researchers have succeeded in applying aerogels to microelectronics: Aerogels based on cellulose nanofibers can effectively shield electromagnetic radiation over a wide frequency range – and they are unrivalled in terms of weight.

Electric motors and electronic devices generate electromagnetic fields that sometimes have to be shielded in order not to affect neighboring electronic...

Im Focus: Gentle wall contact – the right scenario for a fusion power plant

Quasi-continuous power exhaust developed as a wall-friendly method on ASDEX Upgrade

A promising operating mode for the plasma of a future power plant has been developed at the ASDEX Upgrade fusion device at Max Planck Institute for Plasma...

Im Focus: ILA Goes Digital – Automation & Production Technology for Adaptable Aircraft Production

Live event – July 1, 2020 - 11:00 to 11:45 (CET)
"Automation in Aerospace Industry @ Fraunhofer IFAM"

The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM l Stade is presenting its forward-looking R&D portfolio for the first time at...

Im Focus: AI monitoring of laser welding processes - X-ray vision and eavesdropping ensure quality

With an X-ray experiment at the European Synchrotron ESRF in Grenoble (France), Empa researchers were able to demonstrate how well their real-time acoustic monitoring of laser weld seams works. With almost 90 percent reliability, they detected the formation of unwanted pores that impair the quality of weld seams. Thanks to a special evaluation method based on artificial intelligence (AI), the detection process is completed in just 70 milliseconds.

Laser welding is a process suitable for joining metals and thermoplastics. It has become particularly well established in highly automated production, for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International conference QuApps shows status quo of quantum technology

02.07.2020 | Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

 
Latest News

Protective antibodies identified for rare, polio-like disease in children

06.07.2020 | Health and Medicine

How a mutation on the novel coronavirus has come to dominate the globe

06.07.2020 | Life Sciences

Order from noise: how randomness and collective dynamics define a stem cell

06.07.2020 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>