Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A periodic table of molecular knots

06.08.2018

A new study sheds light on a repertoire as-yet-undiscovered molecular knots that could be used in future physico-chemical applications

Consider a short piece of rope: could you guess which knots are more likely to form if you crumple and shake it? Synthetic chemists have long been working on a molecular version of this problem and, so far, have succeeded at synthesizing half a dozen different knots types using molecular self-assembling techniques. But which other knot types will it be possible to realise in the future?


Which new knot types will it be possible to realise in the future? This is the challenging question that SISSA scientists, in association with the University of Padua, have tackled using computer simulations in this new work published in Nature Communications.

Credit: Mattia Marenda and Cristian Micheletti

Usage Restrictions: The image can be only used in connection with this research

This is the challenging question that SISSA scientists, in association with the University of Padua, have tackled using computer simulations in this new work published in Nature Communications. The scientists identified a shortlist, a kind of "periodic table", of the most designable knot types, i.e. those knots that could easily self-assemble under appropriate physical and chemical conditions.

The findings, obtained with computational predictive models, are supported by the latest experimental results and ought to aid the synthesis of as yet undiscovered topologies. This study, and the increasingly predictive capability of molecular modelling techniques, can create novel possible perspectives for future advanced applications, like the construction of sophisticated molecular machines for loading and delivering a nanocargo.

Not just an intellectual challenge

"There is a growing scientific interest in molecules with complex. In this context, the possibility to design and synthesis of novel types of molecular knots is particularly appealing." say Mattia Marenda and Cristian Micheletti, respectively first and last author of this research.

"Until recently, only few types of molecular knots had been synthesised. These were the simplest knots in mathematic tables, i.e. those having at most 5 essential crossings". One could have thus predicted that the next knot type to be synthesized would have had six crossings.

However, in a computational study of 2015, Micheletti and collaborators argued that the simplest and most designable undiscovered knot type was significantly more complex and featured as many as 8 essential crossings. This prediction was experimentally confirmed in 2017 and motivated the current study, which employed a more systematic exploration of the shapes or configurations that can be formed from identical building blocks stitched together in a string-like fashion.

Efficient and reliable simulations

"With these models, we aimed at discovering which new molecular knots types, if any, would be easiest to obtain with current synthetic chemistry techniques, particularly self-assembly. We found that these privileged knot types do exist, but are very rare. Only a dozen of different topologies are realisable among millions of simple knot types. The results of our models had an inherent simplicity" says Marenda.

"The molecular weaving of these knot types is modular and highly symmetric. We used these features as selection criteria to sift the huge combinatorial space of molecular weaving patterns and obtained a shortlist of knot types expected to be easily assembled from few identical building blocks".

"The shortlist is similar to a periodic table, in that it is organised in rows and columns which reflect different aspects of the expected difficulty of practical realization", continues Micheletti. "The results are supported by recent experiments and this suggests that the table could indeed be useful to experimental chemists for choosing the target topologies for further studies and applications".

Nanocargo and molecular machines: possible applications

What are possible long-term results of this research? "At this time" explain Marenda and Micheletti "chemists and physicists have mostly focussed on proof-of-concept demonstrations of the design and synthesis of molecular knots. Nonetheless, interesting applicative avenues have already been suggested". A chief example is the assembly of molecular cages:

"In this case, specific substances could be nested or trapped within weavings of synthetic molecular knots. The latter could then serve as a controllable molecular machine, capable of loading or releasing a nanocargo depending on the specific physico-chemical conditions. These are interesting and appealing perspectives for possible applications in medicine or electronics".

Media Contact

Donato Ramani
ramani@sissa.it
39-040-378-7513

http://www.sissa.it 

Donato Ramani | EurekAlert!
Further information:
http://dx.doi.org/10.1038/s41467-018-05413-z

More articles from Life Sciences:

nachricht Switch-in-a-cell electrifies life
18.12.2018 | Rice University

nachricht Plant biologists identify mechanism behind transition from insect to wind pollination
18.12.2018 | University of Toronto

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Data storage using individual molecules

Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.

Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Pressure tuned magnetism paves the way for novel electronic devices

18.12.2018 | Materials Sciences

New type of low-energy nanolaser that shines in all directions

18.12.2018 | Physics and Astronomy

NASA research reveals Saturn is losing its rings at 'worst-case-scenario' rate

18.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>