Featured Research

from universities, journals, and other organizations

Heat Shock Proteins Provide Protection Against Cataracts

Date:
August 8, 2009
Source:
Technische Universitaet Muenchen
Summary:
Scientists have succeeded in explaining the 3-D molecular architecture of "chaperone" proteins that prevent aggregation and clumping of other proteins in the human eye lens, thus protecting against cataracts. Their findings shed new light on the work of these proteins and may be able to help in the development of new treatments.

This is a three-dimensional reconstruction of ħB crystallin by electron microscopy reveals a sphere-like structure with large openings to the interior of the protein. In the human eye, this molecular machine serves as a "chaperone" to guide protein folding and prevent aggregation such as that responsible for cataracts. Better understanding of this 3-D structure could serve as the basis for comparing healthy and disease-promoting mutants and, based on this, for clarifying the way they function. The scientists hope that this will lead to the discovery of new treatments.
Credit: Dept. of Chemistry, Technische Universitaet Muenchen (TUM) Used by permission of the Dept. of Chemistry, Technische Universitaet Muenchen (TUM), all rights reserved.

The human eye lens consists of a highly concentrated mix of several proteins. Protective proteins prevent these proteins from aggregating and clumping. If this protective function fails, the lens blurs and the patient develops cataracts. Two research groups at the Department of Chemistry of the Technische Universitaet Muenchen (TUM) have succeeded in explaining the molecular architecture of this kind of protective protein.

Their findings, which are published online in the current early edition of PNAS (Proceedings of the National Academy of Sciences), shed new light on the work of these proteins and may be able to help in the development of new treatments.

Cells have a variety of protein complexes that manage vital tasks. The functions of these "molecular machines" depend largely on their three-dimensional structure. In the first instance, proteins are long chains of amino acids, like a long piece of woolen thread. So-called chaperones help them to fold in the desired three-dimensional form after their production. If this folding process fails, the protein thread becomes an inextricable, useless tangle.

Small heat shock proteins (sHsps) are a particularly important group of chaperones. They prevent the clumping of proteins under stress conditions. αB-crystallin and the related sHsp αA-crystallin are the main representatives of the sHsps found in humans. Whereas αA-crystallin mainly occurs in the eye lens, αB-crystallin is also very common in the brain and in the heart and muscle tissue. In the eye lens, they counteract diseases like cataracts. Malfunctions of the αB-crystallin in tissue cells can give rise to cancer and neurological defects, including Alzheimer's disease.

Many research groups have focused their work on the α-crystallins due to their medical relevance. Despite intensive efforts, up to now, none of them have managed to determine the molecular architecture of these proteins. However, TUM biochemists have now succeeded in producing αA-crystallins and αB-crystallins recombinantly in bacteria and in obtaining uniform, clearly-structured complexes. A detailed structural analysis of these proteins was carried out in cooperation with the Chemistry Department's Center of Electron Microscopy. The research groups were able to show for the first time here that, contrary to previous suppositions, αB-crystallin forms a defined globular structure comprising 24 subunits, which are reminiscent of a perforated soccer ball.

Thanks to the identification of the three-dimensional structure of αB-crystallin, which is currently being further refined, the basis has now been established for comparing healthy and disease-promoting mutants and, based on this, for clarifying the way they function. The scientists hope that this will lead to the discovery of new treatments.

This work was supported by the German Research Foundation (DFG grant SFB594, to J.B., M.H., and S.W.) and the Fonds der chemischen Industrie (J.B. and M.H.). J.P. acknowledges a scholarship from the Studienstiftung des deutschen Volkes.


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. Jirka Peschek, Nathalie Braun, Titus M. Franzmann, Yannis Georgalis, Martin Haslbeck, Sevil Weinkauf, Johannes Buchner. The eye lens chaperone %u03B1-crystallin forms defined globular assemblies. PNAS, Early Edition, July 27, 2009 DOI: 10.1073/pnas.0902651106

Cite This Page:

Technische Universitaet Muenchen. "Heat Shock Proteins Provide Protection Against Cataracts." ScienceDaily. ScienceDaily, 8 August 2009. <www.sciencedaily.com/releases/2009/07/090731103328.htm>.
Technische Universitaet Muenchen. (2009, August 8). Heat Shock Proteins Provide Protection Against Cataracts. ScienceDaily. Retrieved September 23, 2014 from www.sciencedaily.com/releases/2009/07/090731103328.htm
Technische Universitaet Muenchen. "Heat Shock Proteins Provide Protection Against Cataracts." ScienceDaily. www.sciencedaily.com/releases/2009/07/090731103328.htm (accessed September 23, 2014).

Share This



More Health & Medicine News

Tuesday, September 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Costs Keep Mounting

Ebola Costs Keep Mounting

Reuters - Business Video Online (Sep. 23, 2014) — The WHO has warned up to 20,000 people could be infected with Ebola over the next few weeks. As Sonia Legg reports, the implications for the West African countries suffering from the disease are huge. Video provided by Reuters
Powered by NewsLook.com
Ebola Cases Could Reach 1.4 Million Within 4 Months

Ebola Cases Could Reach 1.4 Million Within 4 Months

Newsy (Sep. 23, 2014) — Health officials warn that without further intervention, the number of Ebola cases in Liberia and Sierra Leone could reach 1.4 million by January. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Cases to Triple in Weeks Without Drastic Action

WHO: Ebola Cases to Triple in Weeks Without Drastic Action

AFP (Sep. 23, 2014) — The number of Ebola infections will triple to 20,000 by November, soaring by thousands every week if efforts to stop the outbreak are not stepped up radically, the WHO warned in a study on Tuesday. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
5 Ways Men Can Prevent Most Heart Attacks

5 Ways Men Can Prevent Most Heart Attacks

Newsy (Sep. 23, 2014) — No surprise here: A recent study says men can reduce their risk of heart attack by maintaining a healthy lifestyle, which includes daily exercise. 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

 

Health & Medicine

Mind & Brain

Living & Well

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