Featured Research

from universities, journals, and other organizations

Physicists help biologists to understand protein folding

Date:
June 20, 2010
Source:
University of California - Santa Barbara
Summary:
Physicists have created a microscopic device to assist biologists in making very fast molecular measurements that aid the understanding of protein folding. This development may help elucidate biological processes associated with diseases such as Alzheimer's and Parkinson's. Since proteins in the body perform different functions according to their shape, the folding process is considered a key area of study.

Physicists at UC Santa Barbara have created a microscopic device to assist biologists in making very fast molecular measurements that aid the understanding of protein folding. This development may help elucidate biological processes associated with diseases such as Alzheimer's and Parkinson's. Since proteins in the body perform different functions according to their shape, the folding process is considered a key area of study.

Using a microfabricated fluid mixing device built at UCSB's nanofabrication facility, UCSB physicists and their collaborators from the University of Zurich have made the first sub-second, single-molecule measurements of an essential biological molecule known as a chaperonin. The results are published in the Proceedings of the National Academy of Sciences.

"The genes encoded in DNA contain chemical sequences for proteins, which, once they have been synthesized in the cell, fold into molecular machines that perform the basic functions of living things," said Everett Lipman, co-author and assistant professor of physics at UCSB. "Many proteins can fold on their own, but others are prone to misfolding and aggregation, which are thought to cause neurodegenerative diseases such as Alzheimer's and Parkinson's."

Chaperonins are known to assist the folding of other proteins, called substrates, and to prevent aggregation, Lipman explained. GroEL, a member of a large family of chaperonins, works in concert with GroES to encapsulate a substrate protein, isolating it as it folds. Although this process has been studied previously, the mechanism by which the chaperonin functions or fails to function is not yet understood.

Single-molecule experiments provide information about protein folding that would otherwise be obscured by averaging signals from the many billions of unsynchronized molecules in a typical ensemble experiment. Until now, the slow speed of manual mixing prevented single-molecule measurements of folding inside chaperonins at times earlier than a few minutes. This is far slower than the fifth of a second needed for GroEL and GroES to encapsulate their substrate.

UCSB physics graduate student Shawn Pfeil, working with Lipman and fellow student Charlie Wickersham, designed and built a device that enables single-molecule measurements as fast as five milliseconds. Fluids were mixed in a channel one-tenth the size of a human hair. With collaborators Armin Hoffmann and Benjamin Schuler at the Biochemical Institute of the University of Zurich, they measured the folding of rhodanese, an enzyme responsible for detoxification of cyanide, inside the GroEL-GroES chaperone complex.

The results show that -- contrary to what was previously believed -- the fast initial capping of the chaperonin cavity by GroES and the related conformational change of GroEL do not initiate folding of the substrate, explained Lipman. Extensive measurements on time scales from milliseconds to hours indicate that the chaperonin slows the folding of one portion of the rhodanese protein, allowing it to find the correct folded shape while it is protected from aggregation. Further studies using this new method may help to determine whether the failure of chaperonins is responsible for pathogenic aggregation, clumping of protein, that leads to disease.

Lipman has collaborated with Schuler for over a decade. They met while working as postdoctoral fellows at the National Institutes of Health. The new device builds on an earlier device they developed in 2003. "The microfluidic device we used for the 2003 experiment was slow, and it generated a lot of background noise," he said. "By designing a mixer specifically for single-molecule measurements, we were able to obtain the greatly improved time resolution and sensitivity necessary to measure folding inside a chaperonin."


Story Source:

The above story is based on materials provided by University of California - Santa Barbara. Note: Materials may be edited for content and length.


Journal Reference:

  1. H. Hofmann, F. Hillger, S. H. Pfeil, A. Hoffmann, D. Streich, D. Haenni, D. Nettels, E. A. Lipman, B. Schuler. Single-molecule spectroscopy of protein folding in a chaperonin cage. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1002356107

Cite This Page:

University of California - Santa Barbara. "Physicists help biologists to understand protein folding." ScienceDaily. ScienceDaily, 20 June 2010. <www.sciencedaily.com/releases/2010/06/100617132222.htm>.
University of California - Santa Barbara. (2010, June 20). Physicists help biologists to understand protein folding. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2010/06/100617132222.htm
University of California - Santa Barbara. "Physicists help biologists to understand protein folding." ScienceDaily. www.sciencedaily.com/releases/2010/06/100617132222.htm (accessed October 20, 2014).

Share This



More Matter & Energy News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

'Robotic Eyes' Helps Japan's Bipedal Bot Run Faster

'Robotic Eyes' Helps Japan's Bipedal Bot Run Faster

Reuters - Innovations Video Online (Oct. 16, 2014) Japanese researcher uses an eye-sensor camera to enable a bipedal robot to balance itself, while running on a treadmill. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Lockheed Martin's Fusion Concept Basically An Advertisement

Lockheed Martin's Fusion Concept Basically An Advertisement

Newsy (Oct. 15, 2014) Lockheed Martin announced plans to develop the first-ever compact nuclear fusion reactor. But some experts said the excitement is a little premature. Video provided by Newsy
Powered by NewsLook.com
First Confirmed Case Of Google Glass Addiction

First Confirmed Case Of Google Glass Addiction

Buzz60 (Oct. 15, 2014) A Google Glass user was treated for Internet Addiction Disorder caused from overuse of the device. Morgan Manousos (@MorganManousos) has the details on how many hours he spent wearing the glasses, and what his symptoms were. Video provided by Buzz60
Powered by NewsLook.com
Science Proves Why Pizza Is So Delicious

Science Proves Why Pizza Is So Delicious

Buzz60 (Oct. 15, 2014) The American Chemical Society’s latest video about chemistry in every day life breaks down pizza, and explains exactly why it's so delicious. Gillian Pensavalle (@GillianWithaG) has the video. Video provided by Buzz60
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


Space & Time

Matter & Energy

Computers & Math

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