Nano-softball Made Of DNA
2008-04-09 0:00


For quite some time, DNA, the stuff our genes are made of, has also been considered the building material of choice for nanoscale objects. A team led by Günter von Kiedrowski at the Ruhr University in Bochum has now made a dodecahedron (a geometric shape with twelve surfaces) from DNA building blocks. These objects are formed in a self-assembly process from 20 individual trisoligonucleotides, building blocks consisting of a “branching junction” and three short DNA strands.

A regular dodecahedron is a geometric shape made of 12 pentagons of equal size, three of which are connected at every vertex. This results in a structure with 30 edges and 20 vertices. In order to produce a hollow dodecahedral object from DNA, the researchers used 20 “three-legged” building blocks (three DNA strands connected together at one point). The centers of these building blocks represent the vertices of the dodecahedron. The three edges projecting from each vertex are formed when a single strand of DNA converts two neighboring bridging components into a double strand.

In order for this process to result in a dodecahedron and not some other random geometric object, all of the DNA strands must have a different sequence. Among these, there must, however, be pairs of complementary strands that can bind to each other.

By using a computer program, the researchers identified a set of 30 independent, 15-base-pair-long, double-stranded DNA sequences with similar physical properties. The double-stranded sequences were assigned to the individual edges of the dodecahedron and to specific vertices for termination. It was then determined which three single-stranded sequences needed to be attached to each three-legged junction for the predetermined structure to form.

The team synthesized the 20 computed trisoligonucleotides by means of a solid-phase synthesis. The three DNA strands were always attached by way of an aromatic six-membered carbon ring. When mixed in equal parts in a buffer solution, these building blocks do aggregate to form the expected product: regular dodecahedra. Atomic force microscopy images reveal them to be uniform particles with a diameter of about 20 nm. Under pressure, the dodecahedra are quite flexible, the can be deformed like “soft balls” without incurring any damage.

If the trisoligonucleotides are equipped with pendant “arms”, the dodecahedra can be outfitted with additional functional molecules. In this way, highly complex nanoconstructs, resembling little viruses in shape and size, should be accessible in the future. Potential applications range from medical diagnostics to nanoelectronics.

Journal reference: Self-Assembly of a DNA Dodecahedron from 20 Trisoligonucleotides with C3h Linkers, Angewandte Chemie International Edition, doi: 10.1002/anie.200702682. Nr. 14/2008

Adapted from materials provided by Wiley-Blackwell.

Article from:

Related Articles

Latest News from our Front Page

Pressure from the United Patriots Front Stops Mosque Plan
2016-04-28 20:10
Pressure from the United Patriots Front appears to have killed off a mosque development in Narre Warren North. The City of Casey council now looks likely to withhold planning approval for the development in a special meeting set for Tuesday night. A council report, to be considered by councillors on Tuesday, recommends that the approval be blocked. The mosque opponents’ cause has been helped by councillor ...
Police face questions over the influence of the Freemasons
2016-04-28 20:48
South Yorkshire Police today face questions over whether powerful 'secret society' the Freemasons held sway over the force at the time of Hillsborough. Families of victims say that officers who were Masons were promoted into powerful positions despite being ill-equipped, including match commander David Duckenfield. Duckenfield told the fresh inquests he had been a Freemason since 1975 and became head of his ...
England Bans its Own Flag to Avoid Offending Muslims
2016-04-27 2:23
St. George's Cross "racist" towards immigrants Government officials said their city was ‘too multicultural’ to celebrate St George’s Day, England’s version of the 4th of July. The council said that displaying the English flag may have been seen as “racist” towards immigrants.
Half of Western European men descended from one Bronze Age ‘king’
2016-04-27 2:09
Half of Western European men are descended from one Bronze Age ‘king’ who sired a dynasty of elite nobles which spread throughout Europe, a new study has shown. The monarch, who lived around 4,000 years ago, is likely to have been one of the earliest chieftains to take power in the continent. He was part of a new order which emerged in ...
"Local Residents" Are Filmed Stealing Dozens of Bottles of Water at London Marathon Stop
2016-04-25 23:10
Editor's Comment: "Local" residents? Why bother blurring their faces? We know who they are. ... London marathon runners were robbed of dozens of bottled waters when thieves raided a refreshment area armed with trolleys during today's race. Nearby residents - including parents with children - were captured on camera piling up crates of free water handed out by volunteers during the 26-mile event. Marathon ...
More News »