Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'DNA wires' could help physicians diagnose disease

20.08.2012
In a discovery that defies the popular meaning of the word "wire," scientists have found that Mother Nature uses DNA as a wire to detect the constantly occurring genetic damage and mistakes that ¯ if left unrepaired ¯ can result in diseases like cancer and underpin the physical and mental decline of aging.

That topic ¯ DNA wires and their potential use in identifying people at risk for certain diseases ¯ is the focus of a plenary talk here today during the 244th National Meeting & Exposition of the American Chemical Society, the world's largest scientific society. The meeting, which features about 8,600 reports with an anticipated attendance of 14,000 scientists and others continues here through Thursday.

"DNA is a very fragile and special wire," said Jacqueline K. Barton, Ph.D., who delivered the talk. "You're never going to wire a house with it, and it isn't sturdy enough to use in popular electronic devices. But that fragile state is exactly what makes DNA so good as an electrical biosensor to identify DNA damage."

Barton won the U.S. National Medal of Science, the nation's highest honor for scientific achievement, for discovering that cells use the double strands of the DNA helix like a wire for signaling, which is critical to detecting and repairing genetic damage. She is a professor of chemistry and is chair of the division of chemistry and chemical engineering at the California Institute of Technology in Pasadena.

Damage is constantly occurring to DNA, Barton explained ¯ damage that skin cells, for instance, receive from excessive exposure to sunlight or that lung cells get hit with from carcinogens in cigarette smoke. Cells have a natural repair system in which special proteins constantly patrol the spiral-staircase architecture of DNA. They monitor the 3 billion units, or "base pairs," in DNA, looking for and mending damage from carcinogens and other sources.

Barton and other scientists noticed years ago that the DNA architecture chemically resembles the solid-state materials used in transistors and other electronic components. And DNA's bases, or units, are stacked on top of each other in an arrangement that seemed capable of conducting electricity.

"It's like a stack of copper pennies," said Barton. "And when in good condition and properly aligned, that stack of copper pennies can be conductive. But if one of the pennies is a little bit awry ¯ if it's not stacked so well ¯ then you're not going to be able to get good conductivity in it. But if those bases are mismatched or if there is any other damage to the DNA, as can happen with damage that leads to cancer, the wire is interrupted and electricity will not flow properly."

Barton's team established that the electrons that comprise a flow of electricity can move from one end of a DNA strand to the other, just as they do through an electrical wire. In one recent advance, the team was able to send electricity down a 34-nanometer-long piece of DNA. That might not sound like much — a nanometer is one-tenth the width of a human hair. But that is just the right scale for use in medical diagnostic devices and biosensors to pick up on mutations, or changes, in DNA that could lead to cancer and other diseases.

Barton's research suggested that DNA uses its electrical properties to signal repair proteins that fix DNA damage. If the DNA is no longer conducting electricity properly, that would be a signal for repair proteins to do their thing. Barton's team is applying that knowledge in developing "DNA chips," devices that take advantage of DNA's natural electrical conductivity and its ability to bind to other strands of DNA that have a complementary sequence of base units, and thus probe that sequence for damage. Such a DNA chip would help diagnose disease risk by changes in electrical conductivity resulting from mutations or some other damage.

Other plenary talks featured at the 244th National Meeting & Exposition of the American Chemical Society include:
Chad A. Mirkin, Ph.D., "Spherical nucleic acid (SNA) nanostructures: A new platform for intracellular gene regulation"
Buddy D. Ratner, Ph.D., "A 2012 perspective on biocompatibility: The contributions of the chemist"

John T. Santini, Ph.D., "Multireservoir drug therapies … from science to startups"

Barton and colleagues acknowledge funding from the National Institutes of Health.

The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 164,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

Note to journalists: Please report that this research was presented at a meeting of the American Chemical Society.

Abstract

DNA charge transport chemistry offers an opportunity to carry out redox chemistry at a distance and thus provides a powerful platform for signaling, whether in the design of new sensors or in activating responses across the genome. Many experiments have now shown that DNA-mediated charge transport can arise over long molecular distances but in a reaction that is exquisitely sensitive to perturbations in the DNA base stack. Studies are described to illustrate this chemistry, to design new DNA-based sensors, and to characterize how DNA-binding proteins utilize DNA charge transport for long range signaling.

Michael Bernstein | EurekAlert!
Further information:
http://www.acs.org

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>