Featured Research

from universities, journals, and other organizations

Energy within the cell: Energy-saving chaperon Hsp90

Date:
January 13, 2012
Source:
Technische Universitaet Muenchen
Summary:
A special group of proteins, the so-called chaperons, helps other proteins to obtain their correct conformation. Until now scientists supposed that hydrolyzing ATP provides the energy for the large conformational changes of chaperon Hsp90. Now a research team has demonstrated that Hsp90 utilizes thermal fluctuations as the driving force for its conformational changes.

With their specially designed three-color single-molecule FRET (Foerster resonance energy transfer) assay with alternating laser excitation (ALEX) for simultaneous observation of ATP binding and conformational changes professor Hugel and his team could prov, that Hsp90 utilizes thermal fluctuations for its large conformational changes.
Credit: Christoph Ratzke

A special group of proteins, the so-called chaperones, helps other proteins to obtain their correct conformation. Until now scientists supposed that hydrolyzing ATP provides the energy for the large conformational changes of chaperone Hsp90. Now a research team from the Nanosystems Initiative Munich (NIM) could prove that Hsp90 utilizes thermal fluctuations as the driving force for its conformational changes.

Related Articles


The  journal PNAS reports on their findings.

ATP is the major energy source for most organisms and ATPases are the machines, which utilize this fuel, for example to move muscles or cargo in our body. The very abundant chaperone protein Hsp90 has such an ATPase in each of its two monomers. During the last years experiments had suggested that the movement and conformational changes of ATPase proteins are in general strictly linked to ATP binding and hydrolysis (i.e. fuel consumption).

To probe this theory Thorsten Hugel, Professor at the Technische Universitaet Muenchen (TUM) and member of the Nanosystems Initiative Munich (NIM), and his team designed a special three color single-molecule FRET (Fφrster resonance energy transfer) assay with alternating laser excitation (ALEX) for simultaneous observation of ATP binding and conformational changes. Unexpectedly the experiments revealed that binding and hydrolysis of ATP is not correlated with the large conformational changes of Hsp90. Hsp90 is instead a highly flexible machinery driven by thermal fluctuations.

"Thermal fluctuations are random changes in the structure of the protein -- they can be thought of as collisions with water molecules in the environment, which move rather violently at the temperatures in a living organism," says Thorsten Hugel. "Using these clashes to switch back and forth between different conformations, saves Hsp90 valuable ATP." But then what is the task of ATPase in the Hsp90 chaperone? The scientists suspect that co-chaperones and substrate proteins alter the system so that ATP binding or hydrolysis can take a crucial task.

With the newly developed experimental setup, it is now possible to investigate the very complex system in greater detail to resolve this important question. The Munich biophysicists therewith offer a new perspective on the energy conversion in molecular machines.

The work was supported by grants from the DFG (Hu997/9-1, SFB 863) and the Cluster of Excellence Nanosystems Initiative Munich (NIM) and the NanoBio-Technology program of the Elite Network of Bavaria.


Story Source:

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


Journal Reference:

  1. C. Ratzke, F. Berkemeier, T. Hugel. Heat shock protein 90's mechanochemical cycle is dominated by thermal fluctuations. Proceedings of the National Academy of Sciences, 2011; 109 (1): 161 DOI: 10.1073/pnas.1107930108

Cite This Page:

Technische Universitaet Muenchen. "Energy within the cell: Energy-saving chaperon Hsp90." ScienceDaily. ScienceDaily, 13 January 2012. <www.sciencedaily.com/releases/2012/01/120113210612.htm>.
Technische Universitaet Muenchen. (2012, January 13). Energy within the cell: Energy-saving chaperon Hsp90. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2012/01/120113210612.htm
Technische Universitaet Muenchen. "Energy within the cell: Energy-saving chaperon Hsp90." ScienceDaily. www.sciencedaily.com/releases/2012/01/120113210612.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) — The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Kids Die While Under Protective Services

Kids Die While Under Protective Services

AP (Dec. 18, 2014) — As part of a six-month investigation of child maltreatment deaths, the AP found that hundreds of deaths from horrific abuse and neglect could have been prevented. AP's Haven Daley reports. (Dec. 18) Video provided by AP
Powered by NewsLook.com
Dads-To-Be Also Experience Hormone Changes During Pregnancy

Dads-To-Be Also Experience Hormone Changes During Pregnancy

Newsy (Dec. 18, 2014) — A study from University of Michigan researchers found that expectant fathers see a decrease in testosterone as the baby's birth draws near. 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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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