September 30, 2009
100th Protein Structure Solved At Diamond Impacts Our Understanding Of How Insects Smell
Why recognizing sex pheromone components of the silkworm moth at the scale of atoms and molecules impacts on eco-friendly agriculture
New research announced today, Wednesday 30th September, by a team of leading scientists working with the UK's national Synchrotron, Diamond Light Source, could have a significant impact on the development and refinement of new eco-friendly pest control methods for worldwide agriculture.Published in the Journal of Molecular Biology, the study was carried out by Dr Jing-Jiang Zhou and colleagues at the world's oldest agricultural research centre and the largest UK facility, Rothamsted Research, in collaboration with Professor Nick Keep's group from the Institute of Structural and Molecular Biology at Birkbeck, University of London.
Dr Jing-Jiang Zhou, Senior Research Scientist in insect molecular biology at Rothamsted Research, studies insect olfaction and chemical ecology at the molecular level, he explains, "Using Diamond Light Source's intense X-rays, we unraveled the detailed mechanisms linked to pheromone detection which dictates mating behavior in silkworm moths. They are a model organism and any new insights into the working of their olfactory system has repercussions on our global understanding how insects locate mates and their hosts."
Solving this protein structure also represents a significant achievement in the advance of structural biology in the UK and it marks the 100th new structure identified at Diamond since its opening in 2007.
Professor Dave Stuart, Life Sciences Director at Diamond Light Source adds: "It is a milestone and it illustrates the fascinating range of structural biology being undertaken in the UK. Congratulations to the Rothamsted and Birkbeck groups; thanks to productive groups like these, there is currently an exponential growth in the number of structures solved at Diamond."
The importance of understanding how insects 'smell' and how the chemical signals are recognized is useful for many things, but especially for pest control in agriculture. Determining the composition and processes behind the olfactory functions of insects feed directly in to the development and refinement of new pathways to influence insect host locating behaviors. Plants use chemical signals to repel and attract insects and by harnessing a detailed understanding of the signals, farmers can plant companion species to create 'odors' that would make an area very unattractive or attractive to insects according to what they require. This is more commonly known as the push-pull system.
Many insects depend on chemicals like pheromones to communicate with each other and to find a suitable mate. There are two main sex pheromone components bombykol and bombykal in the silkworm moth. Bombykol, the first insect pheromone discovered 50 years ago is the only component involved in mating behavior whereas bombykal is an antagonist.
Dr Jing-Jiang Zhou, adds: "So far, we know that odorant binding proteins [OBPs] within the organism pick up pheromones at pores on the outside of the antenna and carry them through a watery layer to the nerve endings. But it is not clear whether they simply transport and release molecules which bind to olfactory receptors or whether they form a specific OBP- pheromone complex which then activates the receptor. The structures we determined using the crystallography capabilities at Diamond give us a view of how these processes work."
Prof. Stuart explains how crystallography helps: "Studying proteins and the role they play within organisms is like having a 100 locks and keys in front of you and not having any idea as to what fits what"¦By solving the structure of these proteins, we understand more about their function and matching them becomes much easier."
Dr Zhou concludes: "It's not just the farming community which stands to benefit from this work. These new insights will be fed into the development and refinement of biosensors where detection sensitivity is paramount in areas like blood tests. One of our spin-off companies are also investigating how bees can detect some small quantities of explosives and stand to benefit from any knowledge we generate."
Rothamsted Research Institute is funded by BBSRC and Dr Zhou's project is funded by a BBSRC SCIBS initiative grant 'Defining the chemical space for ligands of odorant- binding proteins Ref:BB/D005892/1.
Diamond Light Source is funded by the UK Government through STFC and by the Wellcome Trust. Diamond is a platform for research for the Research Councils and in particular for AHRC, BBSRC,EPSRC, MRC and NERC.
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