Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Researchers build synthetic membrane channels out of DNA: Nanotech structures mimic nature's way of tunneling through cell walls

This 3-D print shows the structure of a functional synthetic membrane channel constructed through DNA nanotechnology -- that is, using DNA molecules as programmable building materials for custom-designed, self-assembling nanometer-scale structures. This DNA-based membrane channel consists of a needle-like stem 42 nanometers long with an internal diameter of just two nanometers, partly sheathed by a barrel-shaped cap. A ring of cholesterol units around the edge of the cap helps the device "dock" to a lipid membrane while the stem sticks through it, forming a channel that appears capable of behaving like a biological ion channel. The device is formed by 54 double-helical DNA domains on a honeycomb lattice.

Credit: Dietz Lab, TU Muenchen; copyright TU Muenchen
This 3-D print shows the structure of a functional synthetic membrane channel constructed through DNA nanotechnology -- that is, using DNA molecules as programmable building materials for custom-designed, self-assembling nanometer-scale structures. This DNA-based membrane channel consists of a needle-like stem 42 nanometers long with an internal diameter of just two nanometers, partly sheathed by a barrel-shaped cap. A ring of cholesterol units around the edge of the cap helps the device "dock" to a lipid membrane while the stem sticks through it, forming a channel that appears capable of behaving like a biological ion channel. The device is formed by 54 double-helical DNA domains on a honeycomb lattice.

Credit: Dietz Lab, TU Muenchen; copyright TU Muenchen

Abstract:
As reported in the journal Science, physicists at the Technische Universitaet Muenchen (TUM) and the University of Michigan have shown that synthetic membrane channels can be constructed through "DNA nanotechnology." This technique employs DNA molecules as programmable building materials for custom-designed, self-assembling, nanometer-scale structures. The researchers present evidence that their nature-inspired nanostructures may also behave like biological ion channels. Their results could mark a step toward applications of synthetic membrane channels as molecular sensors, antimicrobial agents, and drivers of novel nanodevices.

Researchers build synthetic membrane channels out of DNA: Nanotech structures mimic nature's way of tunneling through cell walls

Munich, Germany | Posted on November 20th, 2012

Over the past three decades, researchers have advanced DNA nanotechnology from an intriguing idea to an emerging technology, with a toolbox of methods and a portfolio of nanometer-scale objects designed to demonstrate its potential. What's new here is the claim that DNA nanotech can be used to mimic one of the most widespread and important nanomachines in nature.

To wall off the insides of cells from the outside world, organisms in all three domains of life use the same kind of barrier: an impermeable membrane made from two layers of lipid molecules. Such membranes can also be found within cells, for example encapsulating the nucleus, and even surrounding many kinds of viruses. And to mediate between the different environments on either side of this universal barrier, nature provides a common type of passageway. Membrane channels are tube-like structures made of proteins, which pierce the barriers and regulate the two-way exchange of material and information between the inside and outside. Now researchers have demonstrated the first artificial membrane channel made entirely of DNA, and its characteristics suggest a number of potential applications. "If you want, for example, to inject something into a cell, you have to find a way to punch a hole into the cell membrane, and this device can do that, at least with model cell membranes," says TUM Prof. Hendrik Dietz, a fellow of the TUM Institute for Advanced Study.

In a shape inspired by a natural channel protein, the DNA-based membrane channel consists of a needle-like stem 42 nanometers long with an internal diameter of just two nanometers, partly sheathed by a barrel-shaped cap. A ring of cholesterol units around the edge of the cap helps the device "dock" to a lipid membrane while the stem sticks through it, forming a channel that appears to function like the real thing. TUM Professor Friedrich Simmel, co-coordinator of the Excellence Cluster Nanosystems Initiative Munich, explains: "We have not tested this yet with living cells, but experiments with lipid vesicles show that our synthetic device will bind to a bilayer lipid membrane in the right orientation, so that the stem both penetrates the membrane and holds at the surface, forming a pore."

Further experiments demonstrated that the resulting pores have electrical conductivity comparable to that of a natural cell wall with ion channels, suggesting that they might be able to act like voltage-controlled gates. The results also suggest that transmembrane current could be tuned by adjusting fine structural details of the synthetic channels. To test one potential application of the DNA nanotech devices, the researchers used them as "nanopores" for several different molecular sensing experiments. These confirmed that it is possible, by observing changes in the electrical characteristics, to record the passage of single molecules through synthetic membrane channels made from DNA. Because this approach allows both geometric and chemical tailoring of the membrane channels, it might offer advantages over two other families of molecular sensors, based on biological and solid-state nanopores respectively.

Other conceivable applications remain to be investigated. One notion is to imitate the action of viruses or phages, breaking through the cell walls of targeted bacteria to kill them. In gene therapy, synthetic membrane channels might be used as nano-needles to inject material into cells. Such channels could also be used in basic studies of cell metabolism. Another idea is to harness the so-called ion flux — which in cell membranes moves material in and out through the channel — to drive sophisticated nanodevices inspired by other natural mechanisms. "We might be able to mimic natural ion pumps, transport proteins, and rotary motors like the enzyme responsible for synthesizing ATP," says Dietz. "I love that idea. That's what keeps me running."
###

This work was supported by the German Research Foundation (DFG) via the TUM Institute for Advanced Study, Excellence Clusters NIM (Nanosystems Initiative Munich) and CIPSM (Center for Integrated Protein Science Munich), and SFB 863; by the Federal Ministry of Education and Research (BMBF, Grant 13N10970); by the European Research Council (Dietz, Starting Grant GA256270); and by the National Institutes of Health (Mayer, Grant 1R01GM081705).

Original publication:

Martin Langecker*, Vera Arnaut*, Thomas G. Martin*, Jonathan List, Stephan Renner, Michael Mayer, Hendrik Dietz°, and Friedrich C. Simmel°. Synthetic lipid membrane channels formed by designed DNA nanostructures. Science, vol. 338, issue 6109, pp. 932-936. DOI: 10.1126/science.1225624 (* equal contribution authors; ° co-corresponding authors)

####

About Technische Universitaet Muenchen
Technische Universitaet Muenchen (TUM) is one of Europe's leading universities. It has roughly 480 professors, 9000 academic and non-academic staff, and 31,000 students. It focuses on the engineering sciences, natural sciences, life sciences, medicine, and economic sciences. After winning numerous awards, it was selected as an "Excellence University" in 2006 and 2012 by the Science Council (Wissenschaftsrat) and the German Research Foundation (DFG). The university's global network includes an outpost with a research campus in Singapore. TUM is dedicated to the ideal of a top-level research-based entrepreneurial university.

For more information, please click here

Contacts:
Patrick Regan

49-892-891-0515

Prof. Hendrik Dietz
Technische Universitaet Muenchen
Physics Dept., Walter Schottky Institute / ZNN
Am Coulombwall 4a
85748 Garching, Germany
Tel: +49 89 289 11615

Web: bionano.physik.tu-muenchen.de/

Prof. Friedrich Simmel
Technische Universitaet Muenchen
Physics Dept., Walter Schottky Institute / ZNN
Am Coulombwall 4a
85748 Garching, Germany
Tel: +49 89 289 11611

Web: www.e14.ph.tum.de

Copyright © Technische Universitaet Muenchen

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

Scientists reveal breakthrough in optical fiber communications December 21st, 2014

Atom-thick CCD could capture images: Rice University scientists develop two-dimensional, light-sensitive material December 20th, 2014

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

Instant-start computers possible with new breakthrough December 19th, 2014

Molecular Machines

Creation of 'Rocker' protein opens way for new smart molecules in medicine, other fields December 18th, 2014

Dartmouth researchers create 'green' process to reduce molecular switching waste December 15th, 2014

'Nanomotor lithography' answers call for affordable, simpler device manufacturing October 31st, 2014

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Molecular Nanotechnology

Dartmouth researchers create 'green' process to reduce molecular switching waste December 15th, 2014

New technique allows low-cost creation of 3-D nanostructures December 8th, 2014

Researchers discern the shapes of high-order Brownian motions November 17th, 2014

Manipulating complex molecules by hand: New method in scanning probe microscopy: Jülich researchers create a word using 47 molecules November 6th, 2014

Self Assembly

Revealed: How bacteria drill into our cells and kill them December 2nd, 2014

Live Images from the Nano-cosmos: Researchers watch layers of football molecules grow November 5th, 2014

Outsmarting Thermodynamics in Self-assembly of Nanostructures: Berkeley Lab reports method for symmetry-breaking in feedback-driven self-assembly of optical metamaterials November 4th, 2014

NYU Researchers Break Nano Barrier to Engineer the First Protein Microfiber October 23rd, 2014

Nanomedicine

Creation of 'Rocker' protein opens way for new smart molecules in medicine, other fields December 18th, 2014

Iranian Researchers Produce Electrical Pieces Usable in Human Body December 18th, 2014

Unraveling the light of fireflies December 17th, 2014

First Home-Made Edible Herbal Nanodrug Presented to Pharmacies across Iran December 17th, 2014

Sensors

Promising new method for rapidly screening cancer drugs: UMass Amherst researchers invent fast, accurate new nanoparticle-based sensor system December 15th, 2014

Graphene Applied in Production of Recyclable Electrodes December 13th, 2014

Detecting gases wirelessly and cheaply: New sensor can transmit information on hazardous chemicals or food spoilage to a smartphone December 8th, 2014

Nanosensor to Detect Naproxen Drug Produced in Iran December 6th, 2014

Discoveries

Scientists reveal breakthrough in optical fiber communications December 21st, 2014

Atom-thick CCD could capture images: Rice University scientists develop two-dimensional, light-sensitive material December 20th, 2014

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

Instant-start computers possible with new breakthrough December 19th, 2014

Announcements

Scientists reveal breakthrough in optical fiber communications December 21st, 2014

Atom-thick CCD could capture images: Rice University scientists develop two-dimensional, light-sensitive material December 20th, 2014

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

Instant-start computers possible with new breakthrough December 19th, 2014

Research partnerships

Scientists reveal breakthrough in optical fiber communications December 21st, 2014

Oregon researchers glimpse pathway of sunlight to electricity: Collaboration with Lund University uses modified UO spectroscopy equipment to study 'maze' of connections in photoactive quantum dots December 19th, 2014

Unraveling the light of fireflies December 17th, 2014

Scientists trace nanoparticles from plants to caterpillars: Rice University study examines how nanoparticles behave in food chain December 16th, 2014

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




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE