Nanotechnology Now

Our NanoNews Digest Sponsors
Heifer International



Home > Press > Cell membranes behave like cornstarch and water

Raghuveer Parthasarathy, a professor of physics and member of the UO's Materials Science Institute and Institute of Molecular Biology
Raghuveer Parthasarathy, a professor of physics and member of the UO's Materials Science Institute and Institute of Molecular Biology

Abstract:
Mix two parts cornstarch and one part water. Swirl your fingers in it slowly and the mixture is a smoothly flowing liquid. Punch it quickly with your fist and you meet a rubbery solid -- so solid you can jump up and down on a vat of it.

It turns out that cell membranes — or, more precisely the two-molecule-thick lipid sheets that form the structural basis of all cellular membranes — behave the same way, say University of Oregon scientists.

Cell membranes behave like cornstarch and water

Eugene, OR | Posted on November 3rd, 2010

For decades, researchers have been aware that biological membranes are fluid, and that this fluidity is crucial to allowing the motions and interactions of proteins and other cell surface molecules. The new studies, however, reveal that this state is not the simple Newtonian fluidity of familiar liquids like water, but rather it is viscoelastic. At rest the mixture is very fluid, but when quickly perturbed, it bounces back like rubber.

The discovery is detailed Oct. 25 in the Early Edition of the Proceedings of the National Academy of Sciences, and it strikes down the notion that these biologically important membranes are Newtonian fluids that flow regardless of the stress they encounter.

"This changes our whole understanding of what lipid membranes are," said Raghuveer Parthasarathy, a professor of physics and member of the UO's Materials Science Institute and Institute of Molecular Biology. "We may need to rethink our understanding of how all sorts of the mechanical processes that occur in cell membranes work, like how proteins are pulled from one place to another, how cells respond to stretching and other forces, and how membrane-embedded proteins that serve as channels for chemical signals are able to open and close.

"A lot of these mechanical tasks go awry in various diseases for reasons that remain mysterious," he said. "Perhaps a deeper understanding of the mechanical environment that membranes provide will illuminate why biology functions, or fails to function, in the way it does."

In the project, freestanding membranes of lipids — fatty molecules that form the basis of all cell membranes — were built with lipid-anchored nanoparticles as tracers that could be observed under high-powered microscopes. Close analysis of the trajectories of these particles allowed researchers to deduce the fluid and elastic properties of the membranes under changing conditions.

Leading the experiments were Christopher W. Harland, who earned a doctorate in physics from the UO last summer and is now a postdoctoral researcher at the University of Chicago, and Miranda J. Bradley, then a visiting undergraduate student from Portland Community College and now at Portland State University. Bradley studied in Parthasarathy's lab as part of the UO's Undergraduate Catalytic Outreach & Research Experiences (UCORE) program.

The importance of membrane fluidity has been recognized for decades, but membranes' strange character as a viscoelastic material has gone unnoticed, said Parthasarathy, who is among UO scientists involved in the Oregon Nanoscience and Microtechnologies Institute (ONAMI). "In retrospect, we shouldn't be surprised. Nature uses viscoelasticity in lots of its other liquids, from mucus to tears. Now we've found that it harnesses viscoelasticity in lipid membranes as well."

The Alfred P. Sloan Foundation, Office of Naval Research through ONAMI and National Science Foundation supported the research.

####

About University of Oregon
The University of Oregon is a world-class teaching and research institution and Oregon's flagship public university. The UO is a member of the Association of American Universities (AAU), an organization made up of the 63 leading public and private research institutions in the United States and Canada. The University of Oregon is one of only two AAU members in the Pacific Northwest.

For more information, please click here

Contacts:
Media Contact:
Jim Barlow
director of science and research communications

541-346-3481

Source:
Raghuveer Parthasarathy
assistant professor of physics
541-346-2933

Copyright © University of Oregon

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

Researchers develop artificial building blocks of life March 8th, 2024

How surface roughness influences the adhesion of soft materials: Research team discovers universal mechanism that leads to adhesion hysteresis in soft materials March 8th, 2024

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

Videos/Movies

New X-ray imaging technique to study the transient phases of quantum materials December 29th, 2022

Solvent study solves solar cell durability puzzle: Rice-led project could make perovskite cells ready for prime time September 23rd, 2022

Scientists prepare for the world’s smallest race: Nanocar Race II March 18th, 2022

Visualizing the invisible: New fluorescent DNA label reveals nanoscopic cancer features March 4th, 2022

Possible Futures

Two-dimensional bimetallic selenium-containing metal-organic frameworks and their calcinated derivatives as electrocatalysts for overall water splitting March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Academic/Education

Rice University launches Rice Synthetic Biology Institute to improve lives January 12th, 2024

Multi-institution, $4.6 million NSF grant to fund nanotechnology training September 9th, 2022

National Space Society Helps Fund Expanding Frontier’s Brownsville Summer Entrepreneur Academy: National Space Society and Club for the Future to Support Youth Development Program in South Texas June 24th, 2022

How a physicist aims to reduce the noise in quantum computing: NAU assistant professor Ryan Behunin received an NSF CAREER grant to study how to reduce the noise produced in the process of quantum computing, which will make it better and more practical April 1st, 2022

Nanomedicine

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Researchers develop artificial building blocks of life March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Announcements

What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024

Nanobiotechnology

High-tech 'paint' could spare patients repeated surgeries March 8th, 2024

Researchers develop artificial building blocks of life March 8th, 2024

Curcumin nanoemulsion is tested for treatment of intestinal inflammation: A formulation developed by Brazilian researchers proved effective in tests involving mice March 8th, 2024

The Access to Advanced Health Institute receives up to $12.7 million to develop novel nanoalum adjuvant formulation for better protection against tuberculosis and pandemic influenza March 8th, 2024

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