Scientists at the University of Edinburgh have discovered that the key to treating the condition may lie in an enzyme – a substance essential for metabolism – which is found both in humans and in the sleeping sickness parasite.

The researchers found that this enzyme has a very different structure and mode of action in the parasite compared with humans. This opens up the possibility of drugs being developed which can target the parasite enzyme and block its function, while causing no harm to the patient.

The research team has already discovered chemicals that can block the action of the enzyme in the laboratory and are hopeful that their findings can contribute to development of therapies for the disease. Sleeping sickness, a fatal condition which is spread by the tsetse fly, affects as many as 500,000 people across central Africa. Its symptoms include a disturbed sleep cycle and eventual coma and death.

Professor Malcolm Walkinshaw of the University’s School of Biological Sciences, who led the research, said: “We are optimistic about the possibilities raised by this new discovery and believe it is worth developing new drugs based on targeting this enzyme.

“We are already working on compounds that can prevent the enzyme from functioning and will continue to develop these in the hope that they may one day translate into a treatment.”

The study, carried out in collaboration with the University of Conception in Chile, the University of Montreal, and the Catholic University of Leuven, Brussels, was published in the Journal of Molecular Biology. The work was supported by the Medical Research Council, Wellcome Trust and European Commission.