Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Recognizing pathogenic invaders

24.10.2011
Elucidation of the structure of receptors that detect invading pathogens in moths could aid the diagnosis of infectious fungal diseases

Researchers in Japan have determined the structural basis of the molecular defense system that protects insects from pathogens, which provides clarity on the molecular binding that underpins this defense system.

Insects express pattern recognition receptors (PRRs) that provide an innate ability to detect fungi and plant pathogens. One of the PRRs, â-glucan recognition protein (âGRP), recognizes and binds to carbohydrate molecules called â-glucans that are synthesized by pathogens. Since little is known about how these molecules bind to each other, or about how the binding specificity is achieved, Yoshiki Yamaguchi of the RIKEN Advanced Science Institute and his colleagues used genetic engineering to produce the â-glucan-binding regions of âGRPs from two moth species, Bombix mori and Plodia interpunctella. They determined the structure of the receptors, both on their own and when bound to a â-glucan called laminarihexaose, using x-ray crystallography.

Analysis of the crystal structures revealed that the moth receptors recognize a complex of three laminarihexaoses bound to each other, and that their conformation barely changes when they are bound to laminarihexaoses. The analysis also revealed that the proteins from both species bind to laminarihexaoses in an identical way, via a characteristic structural motif, suggesting that the entire âGRP family shares a common binding mechanism.

Yamaguchi and colleagues also revealed that the laminarihexaose molecules attach to each other with hydrogen bonds that form an ordered and highly stable helical structure. Six precisely arranged monosaccharide (sugar) residues, spread across three chains, interact with the receptor binding site simultaneously, and are essential for the interaction.

To verify their findings, the researchers introduced point mutations at specific locations in the binding region of the Plodia interpunctella receptor. Four of the mutations abolished binding of â-glucan altogether, and four others weakened the binding interaction.

Typically, interactions between carbohydrates and proteins are relatively weak because they involve just two or three monosaccharide residues. The finding that the interaction between the receptors and â-glucan involves six residues explains why this interaction is so strong; it also explains the high specificity of the receptors.

Mammals do not produce â-glucans, but they circulate in the bloodstream of patients with diseases such as invasive aspergillosis, a rapidly progressive and often fatal fungal infection.

“Our findings will be used for the development of diagnosis and monitoring tools with high specificity toward a variety of â-glucans,” says Yamaguchi. “Detecting â-glucans in patients may be helpful for identifying infectious fungi, which could in turn be useful to tailor-make treatments for patients.”

The corresponding author for this highlight is based at the Structural Glycolobiology Team, RIKEN Advanced Science Institute

Reference:
Kanagawa, M., Satoh, T., Ikeda, A., Adachi, Y., Ohno, N. & Yamaguchi, Y. Structural insights into recognition of triple-helical â-glucan by insect fungal receptor. Journal of Biological Chemistry 286, 29158–29165 (2011).

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>