Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Computer simulation shows buckyballs deform DNA

08.12.2005


Soccer-ball-shaped "buckyballs" are the most famous players on the nanoscale field, presenting tantalizing prospects of revolutionizing medicine and the computer industry. Since their discovery in 1985, engineers and scientists have been exploring the properties of these molecules for a wide range of applications and innovations. But could these microscopic spheres represent a potential environmental hazard?



A new study published in December 2005 in Biophysical Journal raises a red flag regarding the safety of buckyballs when dissolved in water. It reports the results of a detailed computer simulation that finds buckyballs bind to the spirals in DNA molecules in an aqueous environment, causing the DNA to deform, potentially interfering with its biological functions and possibly causing long-term negative side effects in people and other living organisms.

The research, conducted at Vanderbilt by chemical engineers Peter T. Cummings and Alberto Striolo (now a faculty member at the University of Oklahoma), along with Oak Ridge National Laboratory scientist Xiongce Zhao, employed molecular dynamics simulations to investigate the question of whether buckyballs would bind to DNA and, if so, might inflict any lasting damage. "Safe is a difficult word to define, since few substances that can be ingested into the human body are completely safe," points out Cummings, who is the John R. Hall Professor of Chemical Engineering and director of the Nanomaterials Theory Institute at Oak Ridge National Laboratory.


"Even common table salt, if eaten in sufficient quantity, is lethal. What we are doing is looking at the mechanisms of interaction between buckyballs and DNA; we don’t know yet what actually happens in the body," he says.

Surprising findings

Despite the caveat, Cummings suggests that his research reveals a potentially serious problem: "Buckyballs have a potentially adverse effect on the structure, stability and biological functions of DNA molecules."

The findings came as something of a surprise, despite earlier studies that have shown buckyballs to be toxic to cells unless coated and to be able to find their way into the brains of fish. Before these cautionary discoveries, researchers thought that the combination of buckyballs’ dislike of water and their affinity for each other would cause them to clump together and sink to the bottom of a pool, lake, stream or other aqueous environment. As a result, researchers thought they should not cause a significant environmental problem.

Cummings’ team found that, depending on the form the DNA takes, the 60-carbon-atom (C60) buckyball molecule can lodge in the end of a DNA molecule and break apart important hydrogen bonds within the double helix. They can also stick to the minor grooves on the outside of DNA, causing the DNA molecule to bend significantly to one side. Damage to the DNA molecule is even more pronounced when the molecule is split into two helices, as it does when cells are dividing or when the genes are being accessed to produce proteins needed by the cell.

"The binding energy between DNA and buckyballs is quite strong," Cummings says. "We found that the energies were comparable to the binding energies of a drug to receptors in cells."

It turns out that buckyballs have a stronger affinity for DNA than they do for themselves. "This research shows that if buckyballs can get into the nucleus, they can bind to DNA," Cummings says. "If the DNA is damaged, it can be inhibited from self-repairing."

Computer simulations

The computer simulations showed that buckyballs make first contact with the DNA molecule after one to two nanoseconds. Once the C60 molecules bind with the DNA, they remained stable for the duration of the simulation.

Researchers tested the most common forms of DNA, the "A" and "B" forms. The "B" form is the most common form. In a stronger saline solution, or when alcohol is added, the DNA structure can change to the "A" form. A third, rarer form, "Z," occurs in high concentrations of alcohol or salt and was not tested.

The researchers found that buckyballs docked on the minor groove of "A" DNA, bending the molecule and deforming the stacking angles of the base pairs in contact with it. The simulations also showed that buckyballs can penetrate the free end of "A" form DNA and permanently break the hydrogen bonds between the end base pair of nucleotides.

As expected, the buckyballs bound most strongly to single helix DNA, causing the most deformation and damage. While buckyballs did bind to "B" form double-strand DNA, the binding did not affect the overall shape of the DNA molecule. More research needed

What the researchers don’t know is whether these worrisome binding events will take place in the body. "Earlier studies have shown both that buckyballs can migrate into bodily tissues and can penetrate cell membranes," Cummings says. "We don’t know whether they can penetrate a cell nucleus and reach the DNA stored there. What this study shows is that if the buckyballs can get into the nucleus they could cause real problems. What are needed now are experimental and theoretical studies to demonstrate whether they can actually get there. Because the toxicity of nanomaterials like buckyballs is not well known at this point, they are regarded in the laboratory as potentially very hazardous, and treated accordingly."

Vivian Cooper | EurekAlert!
Further information:
http://www.vanderbilt.edu

More articles from Life Sciences:

nachricht Building a brain, cell by cell: Researchers make a mini neuron network (of two)
23.05.2018 | Institute of Industrial Science, The University of Tokyo

nachricht Research reveals how order first appears in liquid crystals
23.05.2018 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Research reveals how order first appears in liquid crystals

23.05.2018 | Life Sciences

Space-like gravity weakens biochemical signals in muscle formation

23.05.2018 | Life Sciences

NIST puts the optical microscope under the microscope to achieve atomic accuracy

23.05.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>