Navigation Links
The assembly of protein strands into fibrils
Date:4/11/2010

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 Zrich, 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 Zrich. "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.


'/>"/>

Contact: Giovanni Dietler
giovanni.dietler@epfl.ch
41-216-930-446
Ecole Polytechnique Fdrale de Lausanne
Source:Eurekalert

Related medicine news :

1. Advocates Rally Southland Assembly Health Committee Members to Pass AB 1694
2. Flexible Assembly Systems Announces New Torque Calculator App for the iPhone
3. Wednesday, Dec. 2: News From the 95th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA) in Chicago
4. Leukemia-related protein 16 and colorectal carcinoma
5. Caltech scientists uncover structure of key protein in common HIV subgroup
6. UD team develops new method for producing proteins critical to medical research
7. Proteins in unroasted coffee beans may become next-generation insecticides
8. Protein in Breast Tumors May Predict Chemo Response
9. Tumors Use a Protein to Hide From Immune System
10. Newly identified proteins critical to FA pathway DNA repair function
11. Proteins may point to alcohol use test
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:10/12/2017)... ... October 12, 2017 , ... ... treating sleep apnea using cutting-edge Oventus O2Vent technology. As many as ... disorder characterized by frequent cessation in breathing. Oral appliances can offer significant relief ...
(Date:10/12/2017)... ... 2017 , ... IsoComforter, Inc. ( https://isocomforter.com ), one of the ... new design of the shoulder pad. The shoulder pad provides optimal support and ... pain while using cold therapy. By utilizing ice and water that is circulated from ...
(Date:10/12/2017)... ... October 12, 2017 , ... Information about ... intend to develop to enable prevention of a major side effect of chemotherapy ... especially in pediatric patients. For cisplatin, hearing loss is FDA listed on-label as ...
(Date:10/12/2017)... (PRWEB) , ... October 12, 2017 , ... Leading pediatric ... peers in Washington, D.C., for the 49th Congress of the International Society of ... Vice President of the Center for Cancer and Blood Disorders at Children’s ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... nation's first interactive health literacy software tool, and the Cancer Patient Education Network ... cancer patient education, today announce a new strategic alliance. , As CPEN’s ...
Breaking Medicine News(10 mins):
(Date:9/19/2017)... ZirMed Inc ., a recognized leader in cloud-based revenue cycle ... ranked #1 by its users for the seventh consecutive year ... ZirMed was recognized as the top-ranked end-to-end revenue cycle management ... 200 beds and holds one of the longest #1 ranking ... ...
(Date:9/13/2017)... OrthoAtlanta has been named the official orthopedic and sports ... the 2018 College Football Playoff (CFP) National Championship to be ... Atlanta, Georgia . OrthoAtlanta is proud to ... in many activities leading up to, and including the national ... OrthoAtlanta ...
(Date:9/12/2017)... SAN FRANCISCO , Sept. 12, 2017 /PRNewswire/ ... Lifecycle Management Solutions (VLMS), is pleased to announce ... as a member of its Board of Directors ... 2017. ValGenesis VLMS enables life science companies to ... eliminate the use of paper in this process. ...
Breaking Medicine Technology: