Protein discovery targets cotton bugs

The face of Queensland's multi-million dollar cotton industry could be about to change, thanks to pioneering work being conducted by a University of Queensland scientist.

Professor David Craik, from UQ's Institute for Molecular Bioscience, has discovered a protein that, if inserted into a cotton plant's gene, could protect it from the insatiable and highly destructive appetite of the Helicoverpa family of caterpillars.

Annually, these bugs eat their way through hundreds of tonnes of cotton, destroying not only the plants but the incomes of cotton growers. A natural insecticide, such as the one being developed by Prof. Craik, would prove a boon for these farmers.

"Potentially the caterpillars can destroy 10 to 15% of the crop so the damage it does is enormous," Prof. Craik said.

"Such a gene, if inserted into the cotton, could prove a highly effective and natural insecticide, removing the need to use the chemical sprays that are of such environmental concern.

The agricultural applications of this protein have led to the establishment of a company, Cyclagen, which focuses not only on the insecticide potential of this protein in cotton crops, but will also extend the application to other crops in the future.

Using NMR spectroscopy, Prof. Craik discovered that the shape of this protein was cyclical, which means there were no ends for biological enzymes to attack it and break it down. This structural aspect of the protein, coupled with another unique aspect, cystine knots, makes it very stable in biological systems.

Agriculture isn't the only industry to benefit from the discovery. Because the protein is very stable and resistant to attack from digestive enzymes in the human body, it can be used as a framework for developing drugs that can be taken orally - drugs that would otherwise have to be injected so as to bypass the highly acidic digestive system, such as insulin.

Item provided courtesy of The University of Queensland