Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A Two-Legged Molecule

25.04.2012
A small molecule moves independently along a track

Within each of the cells in our bodies, and between individual cells, there are permanent transport processes occurring over distances ranging from a few nanometers to several millimeters.

One of these cellular “cargo carriers” works by means of molecular motors that “walk” along the filaments of the cellular skeleton (cytoskeleton). British researchers have used these as inspiration to develop a molecular “track”, along which a small molecule can move back and forth like a courier. Their system is described in the journal Angewandte Chemie.

David A. Leigh and a team at the University of Edinburgh (UK) made their track from an oligoethylenimine. The filament contains amino groups that act as “stepping-stones” for the molecular “walker”. The walker is a small molecule (á-methylene-4-nitrostyrene). It resembles a stick figure that has an aromatic six-membered ring of carbon atoms for its torso, a nitro group for its head, and two short hydrocarbon legs.

The molecule is initially bound to the first stepping-stone of the track by one leg. The molecular walker’s movement begins with a ring-closing rearrangement (an intramolecular Michael reaction). This causes the second leg to bind to the neighboring stepping-stone. A second, ring-opening rearrangement reaction (a retro-Michael reaction) then causes the first leg to detach from its stepping-stone. This allows the molecular walker to move along the track step by step.

There is, however, a catch: All of these rearrangement reactions are equilibrium reactions.

If the stepping-stones are chemically equivalent, the tiny walker swings back and forth, lifts one leg and puts it down again, moves forward one step then back again; its movement has no directionality. However, it manages on average an amazingly high 530 “steps” before completely coming off the track. That is significantly more than natural systems like the kinesin motor proteins.

The miniature walker can even carry out a task: The researchers attached an anthracene group to the end of a track with five stepping-stones. As long as the walker stays at the beginning of the track, the anthracene fluoresces. However, if the walker reaches the anthracene end of the track, an electronic interaction between the walker and the anthracene “switches off” the fluorescence. The researchers found that the intensity of the fluorescence slowly sinks by about half. The final intensity is reached after about 6.5 hours, at which point there is an equilibrium between all possible positions of the walker.

The team’s next goal is to develop a walker that uses a “fuel” to march in a predetermined direction to transport cargoes over longer, branched tracks.

About the Author
Professor David Leigh is the Forbes Chair of Organic Chemistry at the University of Edinburgh. He is one of the international leaders in the field of artificial molecular motors and machines. He is a Fellow of the Royal Society (the UK's National Academy of Sciences) and has received the 2007 international Feynman Award for Nanotechnology, and many other distinctions. His group is moving to the University of Manchester in autumn 2012.
Author: David A. Leigh, University of Edinburgh (UK), http://www.catenane.net/
Title: A Small Molecule that Walks Non-Directionally Along a Track Without External Intervention

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201200822

David A. Leigh | Angewandte Chemie
Further information:
http://www.catenane.net/
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton 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: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>