An enzyme found in all living things could hold the key to combating certain deadly diseases, such as sleeping sickness, a new study suggests. Research into the enzyme, which helps cells convert nutrients into energy, has shown that it is activated in different ways in various species. Researchers say this discovery creates an opportunity to design drugs that block activity of the enzyme – known as pyruvate kinase (image) – in species that cause infection. Blocking the parasite’s enzyme would effectively kill the parasite, without affecting the same enzyme in the patient. Findings from the study could lead to new treatments for diseases spread by parasites – including sleeping sickness and Chagas disease – that affect millions of people in the developing world. Researchers say the finding could ultimately help physicians tackle a range of healthcare problems, including antibiotic resistance and some forms of cancer. Scientists used a range of analytical techniques to discover how pyruvate kinase functions in parasites, mammals, and bacteria. They found that the enzyme becomes active in all species in a similar way. A small sugar molecule binds to the enzyme to kick-start the process of nutrient absorption. But each species has a unique mechanism for activating the enzyme, providing opportunities to design drugs that block its activity in individual species. Professor Malcolm Walkinshaw, Chair of Structural Biology at the University of Edinburgh, who led the study, said: "With this discovery, we've found an Achilles heel for sleeping sickness and many other conditions.Login Or Register To Read Full Story