Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unusual carbohydrate structure in the cell walls of tuberculosis bacteria-a new point of attack for drugs?

28.07.2004


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.


"The discovery of this new sugar component in LAM could help in the investigation of its role in mycobacterial infections," says Treumann. "As the sugar is very unusual, enzymes that are necessary for its biosynthesis could be a good point of attack for new tuberculosis medications."

Jaida Harris | alfa
Further information:
http://www.interscience.wiley.com

More articles from Life Sciences:

nachricht Many cooks don't spoil the broth: Manifold symbionts prepare their host for any eventuality
14.10.2019 | Max-Planck-Institut für Marine Mikrobiologie

nachricht Diagnostics for everyone
14.10.2019 | Max-Planck-Institut für Kolloid- und Grenzflächenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel Material for Shipbuilding

A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.

The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...

Im Focus: Controlling superconducting regions within an exotic metal

Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).

Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...

Im Focus: How Do the Strongest Magnets in the Universe Form?

How do some neutron stars become the strongest magnets in the Universe? A German-British team of astrophysicists has found a possible answer to the question of how these so-called magnetars form. Researchers from Heidelberg, Garching, and Oxford used large computer simulations to demonstrate how the merger of two stars creates strong magnetic fields. If such stars explode in supernovae, magnetars could result.

How Do the Strongest Magnets in the Universe Form?

Im Focus: Liquifying a rocky exoplanet

A hot, molten Earth would be around 5% larger than its solid counterpart. This is the result of a study led by researchers at the University of Bern. The difference between molten and solid rocky planets is important for the search of Earth-like worlds beyond our Solar System and the understanding of Earth itself.

Rocky exoplanets that are around Earth-size are comparatively small, which makes them incredibly difficult to detect and characterise using telescopes. What...

Im Focus: Axion particle spotted in solid-state crystal

Scientists at the Max Planck Institute for Chemical Physics of Solids in Dresden, Princeton University, the University of Illinois at Urbana-Champaign, and the University of the Chinese Academy of Sciences have spotted a famously elusive particle: The axion – first predicted 42 years ago as an elementary particle in extensions of the standard model of particle physics.

The team found signatures of axion particles composed of Weyl-type electrons (Weyl fermions) in the correlated Weyl semimetal (TaSe₄)₂I. At room temperature,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Symposium on Functional Materials for Electrolysis, Fuel Cells and Metal-Air Batteries

02.10.2019 | Event News

NEXUS 2020: Relationships Between Architecture and Mathematics

02.10.2019 | Event News

Optical Technologies: International Symposium „Future Optics“ in Hannover

19.09.2019 | Event News

 
Latest News

How to control friction in topological insulators

14.10.2019 | Physics and Astronomy

The shelf life of pyrite

14.10.2019 | Earth Sciences

Shipment tracking for "fat parcels" in the body

14.10.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>