Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Lego proteins revealed: Self-assembling protein complexes based on a single mutation could provide scaffolding for nanostructures

Yeast cells producing a bacterial symmetric protein complex with eight units. When it is not mutated (left), the complex diffuses freely inside the cell, but a single mutation (right) triggers its assembly into long filaments.
CREDIT
Weizmann Institute of Science
Yeast cells producing a bacterial symmetric protein complex with eight units. When it is not mutated (left), the complex diffuses freely inside the cell, but a single mutation (right) triggers its assembly into long filaments. CREDIT Weizmann Institute of Science

Abstract:
When hemoglobin undergoes just one mutation, these protein complexes stick to one another, stacking like Lego blocks to form long, stiff filaments. These filaments, in turn, elongate the red blood cells found in sickle-cell disease. For over 50 years, this has been the only known textbook example in which a mutation causes such filaments to form. According to Dr. Emmanuel Levy and his group in the Weizmann Institute of Science's Structural Biology Department, Lego-like assemblies should have formed relatively frequently during evolution. Could this assembly method be common, or even easy to reproduce? Their answer, which was recently published in Nature, may have implications for both biological research and nanoscience.

Lego proteins revealed: Self-assembling protein complexes based on a single mutation could provide scaffolding for nanostructures

Rehovot, Israel | Posted on August 23rd, 2017

Hemoglobin and a fair number of other protein complexes are symmetric: made of identical units. And since identical units are produced from the same gene, each genetic mutation is repeated multiple times in the complex. Mutations that create sticky patches and are repeated on opposite sides of the complex can induce the proteins to stack into long protein fibers. Unlike amyloid-like protein fibers, the complexes in these stacks do not change shape or unfold in order to assemble.

The stickiness occurs because the mutation substitutes an amino acid that is normally hydrophilic -- "water-loving" -- with one that is hydrophobic -- "water-hating." In the watery environment in which proteins move, the hydrophobic regions on those proteins prefer to interact with one another, like foam bubbles in water.

In their experiments, Levy and his group, including Hector Garcia-Seisdedos, Charly Empereur-Mot (who is now at Conservatoire National des Arts et Métiers in Paris) and Nadav Elad of the Weizmann Institute's Chemical Research Support Department, began with an ultra-symmetric protein complex made up of eight identical units. They followed just one rule for mutating the proteins: Switch a hydrophilic amino acid with a hydrophobic, "sticky," one.

The team initially created proteins with three mutations to two different sticky amino acids and observed Lego-like self-assembly in both cases. Investigating further, the team experimented with each mutation individually and found that one was capable, on its own, of producing the long filaments.

So, are mutations that only do one thing -- increase the stickiness of the protein's surface -- likely to induce Lego-like self-assembly? The researchers mutated 11 additional proteins known to form symmetric complexes - creating 73 different mutations in all -- and produced them in baker's yeast cells, adding a fluorescent protein "label" to enable their visualization. In 30 of these variations, the researchers observed behavior that suggested self-assembly: Around half of these had stacked into long filaments, while the other half were bunched together in a more amorphous way, forming "foci."

If the researchers reproduced the phenomenon of sickle-cell filaments so easily in the lab, why is it not seen more in biomedical research? Levy proposes two answers: Firstly, the team revealed that naturally symmetric proteins evolved to have extra hydrophilic amino acids on their surfaces, thus minimizing the risk of self-assembly. Secondly, says Levy, researchers probably see more Lego assemblies than they think: "Now that researchers know they can evolve so readily, they may look at foci more carefully and see many more biologically relevant Lego-like assemblies."

"Also," he adds, "the filaments are produced so easily in the yeast, they could be good candidates for the scaffolding of nanostructures. Our study was unique in that it did not require complex computational design, nor did we have to scan thousands of mutations to find the one we wanted. We simply started with an existing structure and found a simple strategy to induce the assembly of filaments."

###

Dr. Emmanuel Levy's research is supported by the David and Fela Shapell Family Foundation INCPM Fund for Preclinical Studies; the Henry Chanoch Krenter Institute for Biomedical Imaging and Genomics; the Louis and Fannie Tolz Collaborative Research Project; the Richard Bar Laboratory; and Anne-Marie Boucher, Canada. Dr. Levy is the incumbent of the Recanati Career Development Chair of Cancer Research in Perpetuity.

####

About Weizmann Institute of Science
The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to scientists, students, technicians and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials and developing new strategies for protecting the environment.

For more information, please click here

Contacts:
Gizel Maimon

972-893-43856

Copyright © Weizmann Institute of Science

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

Future electronic components to be printed like newspapers July 20th, 2018

The relationship between charge density waves and superconductivity? It's complicated July 19th, 2018

Sirrus's Issued Patent Portfolio Continues To Accelerate July 18th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

Possible Futures

Future electronic components to be printed like newspapers July 20th, 2018

The relationship between charge density waves and superconductivity? It's complicated July 19th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

Nanomedicine

Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication July 13th, 2018

UMBC researchers develop nanoparticles to reduce internal bleeding caused by blast trauma July 13th, 2018

Researchers identify cost-cutting option in treating nail fungus with nanotechnology: GW researcher Adam Friedman, M.D., studied the potential use of nitric oxide-releasing nanoparticles to improve onychomycosis treatment July 11th, 2018

New sensor technology enables super-sensitive live monitoring of human biomolecules July 3rd, 2018

Discoveries

Future electronic components to be printed like newspapers July 20th, 2018

The relationship between charge density waves and superconductivity? It's complicated July 19th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

Materials/Metamaterials

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides July 13th, 2018

Carbon is the new black: Researchers use carbon nanotubes to develop clothing that can double as batteries July 10th, 2018

High-power electronics keep their cool with new heat-conducting crystals July 6th, 2018

Announcements

Future electronic components to be printed like newspapers July 20th, 2018

The relationship between charge density waves and superconductivity? It's complicated July 19th, 2018

Sirrus's Issued Patent Portfolio Continues To Accelerate July 18th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Future electronic components to be printed like newspapers July 20th, 2018

The relationship between charge density waves and superconductivity? It's complicated July 19th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

Grants/Sponsored Research/Awards/Scholarships/Gifts/Contests/Honors/Records

Future electronic components to be printed like newspapers July 20th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 2018

Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication July 13th, 2018

Nanobiotechnology

UMBC researchers develop nanoparticles to reduce internal bleeding caused by blast trauma July 13th, 2018

Researchers identify cost-cutting option in treating nail fungus with nanotechnology: GW researcher Adam Friedman, M.D., studied the potential use of nitric oxide-releasing nanoparticles to improve onychomycosis treatment July 11th, 2018

New sensor technology enables super-sensitive live monitoring of human biomolecules July 3rd, 2018

Arrowhead Presents New Clinical Data on ARO-AAT at Alpha-1 National Education Conference July 1st, 2018

Research partnerships

Future electronic components to be printed like newspapers July 20th, 2018

The relationship between charge density waves and superconductivity? It's complicated July 19th, 2018

FEFU scientists reported on toxicity of carbon and silicon nanotubes and carbon nanofibers: Nanoparticles with a wide range of applying, including medicine, damage cells of microalgae Heterosigma akashivo badly. July 18th, 2018

In borophene, boundaries are no barrier: Rice U., Northwestern researchers make and test atom-thick boron's unique domains July 17th, 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