Animals and plants have evolved all sorts of chemical tricks that allow them to colonize extreme environments. For species that call Antarctica or the Arctic home, surviving sub-zero temperatures is an essential ability, and chemists have isolated many natural antifreeze compounds from these organisms.
A computer-generated image of the beetle antifreeze xylomannan reveals that one face bristles with oxygen atoms (red), forming a polar surface that helps it to cling to ice crystals. Copyright : 2012 Yukishige Ito
The unusual thing about xylomannan is its constituents. Every natural THF isolated to date is protein based, but xylomannan is a glycan, a long-chain sugar-based compound. “Xylomannan is the first example of a THF biomolecule with little or no protein component,” says Ishiwata. “Its mode of action is not entirely clear, but it should be different to those of common THFs such as antifreeze proteins and glycoproteins.”
To confirm the proposed structure of xylomannan, so that they can begin to study how it interacts with ice crystals, Ishiwata, Ito and their colleagues synthesized what they thought to be a key component of the compound’s sugar-based backbone. Their structural analysis, using nuclear magnetic resonance techniques and molecular modeling, confirmed that the structure matches that of the natural compound. It also hints at the way that xylomannan might stick to ice crystals: one face of xylomannan is much more polar than the other face, making one face hydrophilic and the other hydrophobic..“We propose that the hydrophilic phase of xylomannan might bind to the ice crystal, exposing the hydrophobic phase on the ice crystal’s surface,” says Ishiwata. This hydrophobic surface should repel water molecules away from the ice crystal, stopping it from growing any further. “However, the binding mode is still not clear from our structural analysis,” he adds. To test the theory further, the team now plans to synthesize longer fragments of xylomannan to examine their ice-binding ability.
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences