Featured Research

from universities, journals, and other organizations

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

Date:
July 11, 2012
Source:
Ruhr-Universitaet-Bochum
Summary:
How a transport protein obtains its driving force from the energy storage molecule ATP, has been tracked dynamically. 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).
Credit: Falk Syberg

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. 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.


Story Source:

The above story is based on materials provided by Ruhr-Universitaet-Bochum. Note: Materials may be edited for content and length.


Journal Reference:

  1. F. Syberg, Y. Suveyzdis, C. Kotting, K. Gerwert, E. Hofmann. 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, 2012; 287 (28): 23923 DOI: 10.1074/jbc.M112.359208

Cite This Page:

Ruhr-Universitaet-Bochum. "Tracked step for step: ATP splitting in membrane protein dynamically measured for the first time." ScienceDaily. ScienceDaily, 11 July 2012. <www.sciencedaily.com/releases/2012/07/120711074124.htm>.
Ruhr-Universitaet-Bochum. (2012, July 11). Tracked step for step: ATP splitting in membrane protein dynamically measured for the first time. ScienceDaily. Retrieved April 21, 2014 from www.sciencedaily.com/releases/2012/07/120711074124.htm
Ruhr-Universitaet-Bochum. "Tracked step for step: ATP splitting in membrane protein dynamically measured for the first time." ScienceDaily. www.sciencedaily.com/releases/2012/07/120711074124.htm (accessed April 21, 2014).

Share This



More Plants & Animals News

Monday, April 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mich. Boy Unearths 10,000-Year-Old Mastodon Tooth

Mich. Boy Unearths 10,000-Year-Old Mastodon Tooth

Newsy (Apr. 20, 2014) A 9-year-old Michigan boy was exploring a creek when he came across a 10,000-year-old tooth from a prehistoric mastodon. Video provided by Newsy
Powered by NewsLook.com
Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
Man Claims He Found Loch Ness Monster With... Apple Maps?

Man Claims He Found Loch Ness Monster With... Apple Maps?

Newsy (Apr. 18, 2014) Andy Dixon showed the Daily Mail a screenshot of what he believes to be the mythical beast swimming just below the lake's surface. Video provided by Newsy
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins