It had been known that nematode worms can infect and kill insect pests with the help of a bacterium which they harbour inside their intestine.
The bacterium uses a protein (XptA1) a toxin which helps the nematode to kill and feed on the dead body of the insect. The toxin not only kills the target insect but prevents other predators from eating the body giving free reign to the nematode worms to consume it, multiply and move on. However, until now, researchers had little idea of the make up of XptA1 and thus how it worked. The research team, based at the University of Warwick’s horticultural research arm Warwick HRI, have now been able to reveal the shape of the protein XptA1 and discovered a number of properties that make it a particularly efficient natural insecticide and possible alternative to some commercial insecticides that are facing increased resistance in the insect populations they target.
The researchers at Warwick HRI, together with a team of colleagues with expertise in the Structural Biology group in Biological Sciences and in Chemistry at The University of Warwick, as well as Coventry and Nottingham Universities, found that the protein was formed from four sub units in the shape of a hollow cage or box which is configured to bind well to part of a caterpillar’s gut called “Brush Border Membrane Vesicles” (BBMV).
The XptA1 protein seemed to specifically target the BBMV of caterpillars Pieris Brassicae – (The cabbage white butterfly caterpillar which are pests for many growers). The hollow box structure appears to be a key element of the protein’s design. The hollow shape allows the protein to act as a receptacle for two other proteins (in the case of XptA1 these are XptB1 and XptC1). This forms a poison “complex” which makes the XptA1 300 times more toxic to the caterpillars than it would be by itself. As well as helping collect together the three proteins and attach them to the insect’s gut the researchers think that the box shape of the XptA1 protein possibly also helps protect the poison complex from the acid attack they would face from the high pH values in the insect gut. The researchers also discovered that, while XptA1 was highly selective in that it bound to the cabbage white butterfly caterpillar, there were variants of this family of toxic proteins (such as XptA2) that targeted other insects.
Dr Sarah Lee from the University of Warwick said: “This research gives us crucial new insights into a family of naturally occurring proteins that are toxic to a number of insect pests. They offer an alternative to current commercial protein based insect toxins have been in use for 40 years and are now starting to meet some resistance. This potential new family of protein based insecticides would overcome such resistance as they operate in an entirely different way”
The research has been published in the 9th March issue of The Journal of Molecular Biology Volume 366 Issue 5 pages 1558 – 1568. The paper is titled “Structural Characterisation of the Insecticidal Toxin XptA1, Reveals a 1.15 MDa Tetramer with a Cage-like Structure”
Peter Dunn | alfa
New research recovers nutrients from seafood process water
31.10.2018 | Chalmers University of Technology
Plant Hormone Makes Space Farming a Possibility
17.10.2018 | Universität Zürich
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
16.11.2018 | Health and Medicine
16.11.2018 | Life Sciences
16.11.2018 | Life Sciences