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 Newly designed molecule binds nitrogen
23.02.2018 | Julius-Maximilians-Universität Würzburg

nachricht Atomic Design by Water
23.02.2018 | Max-Planck-Institut für Eisenforschung GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Attoseconds break into atomic interior

A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.

In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...

Im Focus: Good vibrations feel the force

A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.

By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...

Im Focus: Developing reliable quantum computers

International research team makes important step on the path to solving certification problems

Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Basque researchers turn light upside down

23.02.2018 | Physics and Astronomy

Finnish research group discovers a new immune system regulator

23.02.2018 | Health and Medicine

Attoseconds break into atomic interior

23.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>