Even though we have lost much of our fear of tuberculosis in the industrialized countries, according to the WHO about 2 mio. people worldwide die each year of this infectious disease. Researchers at the University of Leeds have now discovered a carbohydrate with an unusual structure in the cell walls of Mycobacterium tuberculosis, the bacterium that causes tuberculosis. This could be a new starting point for pharmaceutical research.
The main component of the cell walls of mycobacteria is a lipoarabinomannan (LAM), a molecule consisting of a branched segment made of many sugar building blocks, which is anchored to the cell wall by a fat-like segment. The sugars involved are almost exclusively arabinose and mannose. LAM plays an important role in infection, because it helps the mycobacteria to invade macrophages, dampen the immune response, and protect the invader from oxidation. Researchers working with Achim Treumann have recently discovered that some of the mannose end groups on the outside of the molecule carry another type of sugar building block, a so called methylthiopentofuranose. This type of sugar consists of five carbon atoms (pento) and one of its usual five oxygen atoms is replaced by a sulfur atom (thio), which is also attached to a methyl group (-CH3). This discovery is astonishing because this is the first time that a methylthiosugar has been identified as a component of a polysaccharide. The sulfur atom may be responsible for the protection from oxidation provided by LAM.
However, this sugar is astonishing for another reason: it has an unexpected configuration. Like many sugars, it contains a five-membered ring made of four carbon atoms and one oxygen atom (furanose). There are eight different possibilities for the exact configuration of such a five-membered ring, because each of the four carbon atoms is attached to a further group of atoms, which could lie above or below the surface of the ring. Treumann and his co-workers took on the task of synthesizing all of the eight variations. NMR spectroscopic comparison of the eight sugars with the "original" natural form then allowed the team to identify the correct structure. In this case it has the "xylo" configuration. This is unusual, since sugars with the xylo configuration are usually only found in plants, not in bacteria.
Jaida Harris | alfa
Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University
Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.
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...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences