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.
New type of photosynthesis discovered
17.06.2018 | Imperial College London
New ID pictures of conducting polymers discover a surprise ABBA fan
17.06.2018 | University of Warwick
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
15.06.2018 | Materials Sciences
15.06.2018 | Ecology, The Environment and Conservation
15.06.2018 | Power and Electrical Engineering