Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > The assembly of protein strands into fibrils

Abstract:
Researchers at ETH Zürich, EPF Lausanne and at the University of Fribourg have evidenced a basic general mechanism describing how filamentous proteins assemble into ribbon like structures, the so-called Amyloid fibrils. Combining experiments and theory, they could explain how denatured milk proteins assemble into ribbon like structures composed of up to five filaments. These findings are shining a surprisingly new light on the assembly of these proteins.

The assembly of protein strands into fibrils

Switzerland | Posted on April 19th, 2010

The Atomic Force Microscope depicts on its screen the few nanometer thick and few micrometer long fibers as white flexible sticks, crisscrossing the surface on which they are deposited. The very peculiar property of these proteins lies in fact that they can self assemble into complex ribbon-like twisted fibers.

Researchers at ETH Zürich, EPF Lausanne and University of Fribourg have teamed up to take Atomic Force Microscopy images of the fibers and to analyze them using concepts from polymer physics and theoretical modeling. This combination of expertise has lead them to propose a set of general rules governing the assembly of filaments into thicker and twisted ribbon like fibers. Their results are published in the current issue of the scientific journal Nature Nanotechnology. "The model that we propose is extremely precise in its predictions", says Raffaele Mezzenga, Professor of Food and Soft Materials Sciences at the ETH Zürich. "Up to now there was no such exact and general model for the formation of Amyloid fibers", continues Giovanni Dietler, Professor of Physics of Living Matter, at the EPF Lausanne.

The structure of the Amyloid fibers as it was unveiled by the experiments, surprised the researchers. Single proteins build the long filaments and subsequently the filaments assemble side by side to form the ribbon-like twisted fibers.

Mezzenga explains that the ribbon-like structure is the logic consequence of the strong charge carried by the building blocks of the fibers. In fact, the single proteins feel a strong mutual repulsion preventing them to pack and the ribbon structure is the only one that permits to limit this repulsion. Presently one missing information in the present model, is the exact nature of the short range attraction between the building blocks that drives in the first place the assembly among the protein filaments. Scientists agree that along the filaments there are charge-less domains of hydrophobic character (water repellant) that are the source of the short-range attraction. So there is a balance between attractive and repulsive interactions and the results is the ribbon like twisted conformation.

Self-organizing proteins are common in living matter and they are found in large aggregates for example in blood coagulation. Spherical like proteins are used in food industry as emulsifiers, gelling and foaming agents and in vitro they form Amyloid like structures. These latter fibers have properties (elasticity, solubility, etc) favorable for food texturing or to produce special structures. The milk protein beta-lactoglubulin studied by Mezzenga and his colleagues is at the beginning spherical and by a heat treatment accompanied by acid environment it aggregates into the filamentous structures. Beta-lactoglobulin is an important component of the milk serum and therefore very relevant for food industry.

The knowledge gained by the scientists on this food protein can potentially benefit medical sciences. In fact Amyloid-like fibers appear in humans affected by neurodegenerative diseases, like Alzheimer- or Creutzfeldt-Jakob disease. These human fibers, although made out of a very different proteins, are also ribbon-like and twisted and their assembly into long aggregates is presently under intense scrutiny. The model proposed by the team could also help to understand the genesis and development of theses diseases.

####

For more information, please click here

Copyright © Ecole Polytechnique Federale de Lausanne

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Basque researchers turn light upside down February 23rd, 2018

Stiffness matters February 23rd, 2018

Imaging individual flexible DNA 'building blocks' in 3-D: Berkeley Lab researchers generate first images of 129 DNA structures February 22nd, 2018

'Memtransistor' brings world closer to brain-like computing: Combined memristor and transistor can process information and store memory with one device February 22nd, 2018

Possible Futures

Basque researchers turn light upside down February 23rd, 2018

Stiffness matters February 23rd, 2018

Developing reliable quantum computers February 22nd, 2018

Imaging individual flexible DNA 'building blocks' in 3-D: Berkeley Lab researchers generate first images of 129 DNA structures February 22nd, 2018

Self Assembly

Liquid crystal molecules form nano rings: Quantized self-assembly enables design of materials with novel properties February 7th, 2018

Particle size matters for porous building blocks: Rice University scientists find porous nanoparticles get tougher under pressure, but not when assembled December 19th, 2017

Physicists gain new insights into nanosystems with spherical confinement: Enormous potential for the targeted delivery of pharmaceutical agents and the creation of tailored nanoparticles July 27th, 2017

Oddball enzyme provides easy path to synthetic biomaterials May 17th, 2017

Nanomedicine

Stiffness matters February 23rd, 2018

Histology in 3-D: New staining method enables Nano-CT imaging of tissue samples February 22nd, 2018

Imaging individual flexible DNA 'building blocks' in 3-D: Berkeley Lab researchers generate first images of 129 DNA structures February 22nd, 2018

Arrowhead Receives Regulatory Clearance to Begin Phase 1 Study of ARO-AAT for Treatment of Alpha-1 Liver Disease February 22nd, 2018

Discoveries

Basque researchers turn light upside down February 23rd, 2018

Histology in 3-D: New staining method enables Nano-CT imaging of tissue samples February 22nd, 2018

Developing reliable quantum computers February 22nd, 2018

Imaging individual flexible DNA 'building blocks' in 3-D: Berkeley Lab researchers generate first images of 129 DNA structures February 22nd, 2018

Announcements

Basque researchers turn light upside down February 23rd, 2018

Stiffness matters February 23rd, 2018

Histology in 3-D: New staining method enables Nano-CT imaging of tissue samples February 22nd, 2018

Developing reliable quantum computers February 22nd, 2018

Food/Agriculture/Supplements

Graphene on toast, anyone? Rice University scientists create patterned graphene onto food, paper, cloth, cardboard February 13th, 2018

Silk fibers could be high-tech ‘natural metamaterials’ January 31st, 2018

Nanowrinkles could save billions in shipping and aquaculture Surfaces inspired by carnivorous plants delay degradation by marine fouling January 17th, 2018

Rice U.'s one-step catalyst turns nitrates into water and air: NSF-funded NEWT Center aims for catalytic converter for nitrate-polluted water January 5th, 2018

Nanobiotechnology

Stiffness matters February 23rd, 2018

Histology in 3-D: New staining method enables Nano-CT imaging of tissue samples February 22nd, 2018

Imaging individual flexible DNA 'building blocks' in 3-D: Berkeley Lab researchers generate first images of 129 DNA structures February 22nd, 2018

Arrowhead Receives Regulatory Clearance to Begin Phase 1 Study of ARO-AAT for Treatment of Alpha-1 Liver Disease February 22nd, 2018

Research partnerships

Basque researchers turn light upside down February 23rd, 2018

Computers aid discovery of new, inexpensive material to make LEDs with high color quality February 20th, 2018

Rutgers-Led Innovation Could Spur Faster, Cheaper, Nano-Based Manufacturing: Scalable and cost-effective manufacturing of thin film devices February 14th, 2018

Understanding brain functions using upconversion nanoparticles: Researchers can now send light deep into the brain to study neural activities February 14th, 2018

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project