Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineers build DNA ’nanotowers’ with enzyme tools

13.10.2005


Duke engineers have added a new construction tool to their bio-nanofabrication toolbox. Using an enzyme called TdTase, engineers can vertically extend short DNA chains attached to nanometer-sized gold plates. This advance adds new capability to the field of bio-nanomanufacturing.



"The process works like stacking Legos to make a tower and is an important step toward creating functional nanostructures out of biological materials," said Ashutosh Chilkoti, associate professor of biomedical engineering at Duke’s Pratt School of Engineering.

The prefix nano means a billionth and refers to the billionth-of-a-meter scale of such structures.


Last year, Chilkoti and his team demonstrated an enzyme-driven process to "carve" nanoscale troughs into a field of DNA strands. By combining this technique with the new method of adding vertical length to the DNA strands, they can now create surfaces with three-dimensional topography.

"The development of bio-nanotechnological tools and fabrication strategies, as demonstrated here, will ultimately allow the automated study of biology at the molecular scale and will drive our discovery and understanding of the basic molecular machinery that defines life," said Stefan Zauscher, assistant professor of mechanical engineering and materials science.

This research was published online on Sept. 27, 2005, and will be published in the print Journal of the American Chemical Society (JACS). The article is available at: http://pubs3.acs.org/acs/journals/doilookup?in_doi=10.1021/ja052491z. It is funded by the National Science Foundation.

The authors include Chilkoti, Zauscher, postdoctoral fellow Dominic Chow and graduate student Woo-Kyung Lee.

"Compared with semi-conductor fabrication, bio-nanomanufacturing is in the stone age. There are few tools for working with bio building blocks that work well in water, the natural milieu of biomolecules," Chilkoti said. "And it makes little sense to blindly copy the semi-conductor industry because their techniques don’t work with water-based materials," he said. "So Duke is creating the tools that will make bio-manufacturing possible at an industrial scale."

The team starts with a forest of short DNA strands that cover nanoscale patches of gold, lithographed onto a silicon substrate. The researchers then submerge the substrate in a solution that contains the TdTase (terminal deoxynucleotidyl transferase) enzyme, a cobalt catalyst and the molecular building blocks, called nucleotides, of DNA chains.

Over an hour, the TdTase enzyme grabs the free-floating nucleotides and builds nanoscale "towers" above the surface by extending each DNA strand, increasing its height a hundredfold. In addition, the process works at room temperature in an incubator that maintains humidity, Chilkoti said.

"Working with water-based biological materials requires a humidity-controlled environment, but it is a plus for industry that this surface-initiated polymerization works at room temperature. No special heating or cooling is needed," he said.

"The process is like a surface-initiated polymerization reaction in polymer chemistry, with the important difference that it uses biological materials and is enzymatically catalyzed," adds Zauscher. "Developing the tools to harness biological reactions on the molecular scale opens a whole new arena for materials syntheses."

Biologists have known about the TdTase enzyme for decades, but it has only been used for a few specialized tasks in molecular biology, Chilkoti said. His group was interested in the enzyme because it doesn’t just copy DNA, it builds DNA.

"Biologists call the TdTase enzyme promiscuous because it just builds and builds using whatever is available. We now recognize the enzyme offers us fabulous flexibility for bioengineering. We can use it with any sequence of DNA we need," Chilkoti said.

The Duke team sees enzymes as a rich source of tools for bio-nanomanufacturing. "Enzymes are the body’s production factories, so it makes sense to copy nature’s tools and use them in much the same way. We are trying to bring as many different enzymes as possible to bear on the biomanufacturing problem," Chilkoti said. "The new fabrication strategy allows exquisite control over the structure and composition of the DNA nanostructures, a prospect that offers interesting possibilities for bionanofabrication as it allows specific molecular adapters to be encoded along the vertical direction of the DNA chains," said Zauscher.

Chilkoti said the next step towards bio-nanofabrication is to create a little crane to pick up, move and place biological molecules in precise locations on three-dimensional DNA surfaces.

"When we can place molecules in the right configuration, then we can get them to function. At that point, we can design and create biological machines that accomplish something," he said.

Deborah Hill | EurekAlert!
Further information:
http://www.duke.edu
http://www.cbimms.duke.edu/

More articles from Life Sciences:

nachricht Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine

nachricht New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus 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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Study shines light on brain cells that coordinate movement

26.06.2017 | Life Sciences

Smooth propagation of spin waves using gold

26.06.2017 | Physics and Astronomy

Switchable DNA mini-machines store information

26.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>