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
Forest Management Yields Higher Productivity through Biodiversity
14.10.2016 | Technische Universität München
Farming with forests
23.09.2016 | University of Illinois College of Agricultural, Consumer and Environmental Sciences (ACES)
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering