Featured Research

from universities, journals, and other organizations

Nanomachines in the powerhouse of the cell: Architecture of the largest protein complex of cellular respiration elucidated

Date:
July 5, 2010
Source:
Albert-Ludwigs-Universität Freiburg
Summary:
Scientists in Germany have elucidated the architecture of the largest protein complex of the cellular respiratory chain.They discovered an unknown mechanism of energy conversion in this molecular complex. The mechanism is required to utilize the energy contained in food.

The structural model of mitochondrial complex I provides new insights in energy conversion at nanoscale. A molecular coupling device links pump modules in the membrane arm of the huge enzyme complex.
Credit: Image courtesy of Albert-Ludwigs-Universität Freiburg

Scientists of the University of Freiburg and the University of Frankfurt have elucidated the architecture of the largest protein complex of the cellular respiratory chain.They discovered an unknown mechanism of energy conversion in this molecular complex. The mechanism is required to utilize the energy contained in food.

After ten years of research work, the x-ray crystallographic analysis of the huge and most complicated protein complex of the mitochondrial respiratory chain was successful. The complex contains more than 40 different proteins, marks the entry to cellular respiration and is thus also called mitochondrial complex I. The results are published in the current online-edition of the journal Science.

A detailed understanding of the function of complex I is of special medical interest. Dysfunction of the complex is implicated in several neurodegenerative diseases such as Parkinson´s disease or Alzheimer´s disease, and also with the physiological processes of biological aging, in general. The work of Prof. Carola Hunte of the Freiburg Institute for Biochemistry and Molecular Biology and the Freiburg excellence centre BIOSS (Centre for Biological Signalling Studies) in cooperation with Prof. Ulrich Brandt, Professor for Molecular Bioenergetics and member of the excellence centre „Macromolecular Complexes" and Dr. Volker Zickermann of his research group is a major step forward to this understanding.

The energy metabolism takes place in the so-called powerhouses of the cell, the mitochondria. They transduce the energy taken up as food into adenosine triphosphate, in short ATP, which is the universal energy currency of life. A chain of five complicated molecular machines in the mitochondrial membrane are responsible for the energy conversion. The production of ATP in mitochondria requires so many steps, as it is in principal a Knallgasreaction. In a laboratory experiment, hydrogen and oxygen gas would react in an explosion and the energy contained would be released as heat. In biological oxidation, the energy will be released by the membrane bound protein complexes of the respiratory chain in a controlled manner in small packages. Comparable to a fuel cell, this process generates an electrical membrane potential, which is the driving force of ATP synthesis. The total surface of all mitochondrial membranes in a human body covers about 14.000 square meter. This accounts for a daily production of about 65 kg of ATP.

The now presented structural model provides important and unexpected insights for the function of complex I. A special type of „transmission element," which is not known from any other protein, appears to be responsible for the energy transduction within the complex by mechanical nanoscale coupling. Transferred to the technical world, this could be described as a power transmission by a coupling rod, which connects for instance the wheels of a steam train. This new nano-mechanical principle will now be analysed by additional functional studies and a refined structural analysis.


Story Source:

The above story is based on materials provided by Albert-Ludwigs-Universität Freiburg. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Hunte, V. Zickermann, U. Brandt. Functional Modules and Structural Basis of Conformational Coupling in Mitochondrial Complex I. Science, 2010; DOI: 10.1126/science.1191046

Cite This Page:

Albert-Ludwigs-Universität Freiburg. "Nanomachines in the powerhouse of the cell: Architecture of the largest protein complex of cellular respiration elucidated." ScienceDaily. ScienceDaily, 5 July 2010. <www.sciencedaily.com/releases/2010/07/100702100414.htm>.
Albert-Ludwigs-Universität Freiburg. (2010, July 5). Nanomachines in the powerhouse of the cell: Architecture of the largest protein complex of cellular respiration elucidated. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2010/07/100702100414.htm
Albert-Ludwigs-Universität Freiburg. "Nanomachines in the powerhouse of the cell: Architecture of the largest protein complex of cellular respiration elucidated." ScienceDaily. www.sciencedaily.com/releases/2010/07/100702100414.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) — The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) — The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) — President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) — Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
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