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 What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>