Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Deadly infectious entity of prions discovered


The mysterious, highly infectious prions, which cause the severe destruction of the brain that characterizes "mad cow disease" and several human brain degenerative disorders, can be rendered harmless in the laboratory by a slight alternation of the three-dimensional conformation or shape of the prion protein’s structure.

The discovery, which opens up new directions for researchers studying the currently untreatable prion diseases in humans and animals, is reported in this week’s Nature by Salk Institute scientist Roland Riek and colleagues, along with collaborators in France and Switzerland.

Riek and his colleagues used a fungus as a model system because its prions are easier to isolate and work with than are the prions from humans and other mammals. "It’s a fantastic system to study the structural components of prions and measure infectivity," Riek said.

"This discovery is very interesting from a basic scientific point of view because it shows that a specific conformation of the prion protein is the infectious entity, and also that we can easily destroy the prion’s infectivity by altering its shape," said Riek. "We now need to find out if this is also the case in mammalian prions."

Identified only about 25 years ago, prions are highly unusual infectious agents that sit on the outside of membranes of the cells of many organisms including the human.

So tiny that they cannot been visualized even with the most powerful microscopes, prion proteins exist in two forms in nature: a normal (non-infectious) shape and the abnormal structure that occurs in mad cow disease, scrapie, kuru and several other brain infections.

Most prion infections begin when the normal shape, for reasons unknown, spontaneously changes into the infectious form that kills brain cells. The infection is spread through a chain reaction like process that begins when the first abnormal prion "tags" a prion that has a normal conformation and forces it to adopt the abnormal prion shape. This new rogue prion joins in the game of "tag," by forcing another normal prion into the abnormal form.

Previous studies revealed that a prion’s switch from a normal to the infectious form is associated with a change in the three-dimensional folded shape, or conformation, of the prion’s protein structure. Building on research that identified the part of the prion protein that made a fungal prion infectious, Riek and colleagues discovered that this critical region forms a flat structure called a beta-sheet.

Using a genetic engineering technique called point mutation to change one at a time each amino acid component of the prion protein, the Salk scientists created a variety of different versions of the prion to determine whether the flat shape of the beta-sheet itself was necessary for a prion to be infectious.

The Salk team found that destroying the shape of the beta-sheet rendered the prion harmless. It was no longer able to spread throughout the fungal cell and "tag" other prions, causing them to become infectious.

This research opens up new directions for researchers studying prion diseases in humans and other animals, since targeting the beta-sheet shape might turn out to be a strategy for controlling the feared and untreatable brain-wasting prion diseases such as bovine spongiform encephalopathy.

The study also may help to improve our understanding of such neurodegenerative diseases as Alzheimer’s, in which brain cells gradually "silt up" with structures similar to the prion beta-sheet that are connected to brain cell death.

Cathy Yarbrough | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Strong, steady forces at work during cell division
20.10.2016 | University of Massachusetts at Amherst

nachricht Disturbance wanted
20.10.2016 | Max Delbrück Center for Molecular Medicine in the Helmholtz Association

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Innovative technique for shaping light could solve bandwidth crunch

20.10.2016 | Physics and Astronomy

Finding the lightest superdeformed triaxial atomic nucleus

20.10.2016 | Physics and Astronomy

NASA's MAVEN mission observes ups and downs of water escape from Mars

20.10.2016 | Physics and Astronomy

More VideoLinks >>>