Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


A Two-Legged Molecule

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),
Title: A Small Molecule that Walks Non-Directionally Along a Track Without External Intervention

Angewandte Chemie International Edition, Permalink to the article:

David A. Leigh | Angewandte Chemie
Further information:

More articles from Life Sciences:

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

nachricht Here comes the long-sought-after iron-munching microbe
25.10.2016 | Max-Planck-Institut für marine Mikrobiologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

First-time reconstruction of infectious bat influenza viruses

25.10.2016 | Life Sciences

Novel method to benchmark and improve the performance of protein measumeasurement techniques

25.10.2016 | Life Sciences

Amazon rain helps make more rain

25.10.2016 | Life Sciences

More VideoLinks >>>