Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers discover protein that dissolves amyloid fibers

21.05.2004


Amyloid fibers, those clumps of plaque-like proteins that clog up the brains of Alzheimer’s patients, have perplexed scientists with their robust structures. In laboratory experiments, they are able to withstand extreme heat and cold and powerful detergents that cripple most other proteins. The fibers are in fact so tough that researchers now are exploring ways that they can be used in nanoscale industrial applications. While they are not necessarily the cause of Alzheimer’s, they are associated with it and with many other neurological conditions, and researchers don’t yet have a way to assail these resilient molecules.



A study published this week in the advance online publication of the journal Science suggests that yeast may succeed where scientists have not. The research by a team at Whitehead Institute for Biomedical Research reports on a natural biological process by which yeast cells dismantle amyloid fibers.

"These proteins are remarkably stable," says Susan Lindquist, director of Whitehead and lead researcher on the project. "This is the first time that anyone has found anything that can catalytically take apart an amyloid fiber."


The finding follows years of study that has focused on a yeast protein called Sup35, a protein that helps cells translate genetic information into strings of amino acids – the building blocks of protein molecules. Sometimes Sup35 suddenly forms amyloid fibers similar to those found in Alzheimer’s patients. In yeast, however, this doesn’t kill the cell. Rather, it is part of the cell’s normal biology, changing the types of proteins that the cell makes – changes that can sometimes be beneficial.

Previous research in the Lindquist lab described how a protein called Hsp104 seemed to affect Sup35’s ability to form amyloid fibers. When a yeast cell contained either high amounts of Hsp104 or none at all, amyloid fibers never formed. But when Hsp104 levels were small, the fibers flourished.

While these types of relationships between chemicals aren’t unheard of, "it was counter-intuitive. Both high levels of Hsp104 and the absence of Hsp104 caused the same effect. That certainly made us want to figure out what was going on," says Lindquist, who is also a professor of biology at MIT. "It was hard to come up with a definitive experiment in a living cell that would explain this sort of thing."

In this new study, Lindquist and postdoctoral researcher James Shorter isolated Sup35 and Hsp104. Here they saw that small amounts of Hsp104 catalyzed the formation of amyloid fibers, but large levels of the protein actually caused the fibers to dissolve.

"Given their resilient structure, the fact that a protein can take apart these amyloids is remarkable," says Lindquist. "It has huge implications for our understanding of the protein folding process in amyloid-related conditions."

This research also may contribute to scientists’ understanding of evolution. Prions, those infectious proteins implicated in conditions such as mad cow disease, are a subclass of amyloids. In yeast cells, Sup35 technically is a prion, although it is not toxic to the cell. Many researchers suspect that because prions have been so well conserved in yeast for hundreds of thousands of years, they must serve some sort of evolutionary purpose – and that’s where Hsp104 comes in.

Hsp104 belongs to a class of proteins that sometimes are influenced by environmental factors. It is conceivable, Shorter explains, that a yeast cell in one type of environment can experience an abundance of Hsp104, which would then keep Sup35 from forming amyloid fibers in that cell. But put that cell in a different environment and the result may be a more moderate level of Hsp104 that would, in turn, create amyloid fibers in Sup35, changing how that protein functions and ultimately altering the cell’s biology. And because these changes could then be passed on to subsequent generations of cells, this, the scientists note, would be an example of environment guiding the evolutionary process.

"This is speculation that hasn’t been demonstrated yet," says Shorter. "For obvious reasons it’s hard to prove any evolutionary argument. But this paper is one indication that this might be the case."

David Cameron | EurekAlert!
Further information:
http://www.wi.mit.edu/home.html

More articles from Life Sciences:

nachricht Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?
26.05.2017 | Paul-Ehrlich-Institut - Bundesinstitut für Impfstoffe und biomedizinische Arzneimittel

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>