Quinones are a broad class of molecules that help convert free energy to adenine triphosphate (ATP), the energy currency used in all organisms. However the way that quinones help convert energy is still a mystery. Leslie Dutton and colleagues from the University of Pennsylvania have created a naphthoquinone amino acid (Naq) to investigate the way quinones work. 

'The electrochemical properties of Naq are close to matching those of quinones used by chloroplast and mitochondrial energy conversion proteins' Dutton explains. He predicts that artificial proteins containing this molecule could be used to capture energy as efficiently as natural systems, 'but without their vast complexity and fragility.' 

This molecule could also help scientists investigate oxidative stress, a tissue damaging process involved in diseases such as atherosclerosis, Parkinson's disease and Alzheimer's disease. According to Dutton, quinones are thought to be both harmful and beneficial when it comes to oxidative stress. Damage is caused by oxygen reactive species (such as free radicals). Quinones are thought to create these and to clear them up, but the mechanism for this is unclear. Dutton believes that Naq could provide an insight into the way oxygen reactive species are generated and quenched in cells. This could lead to the creation of protein based pharmaceuticals to reduce or mend tissue damage caused by oxidative stress. 

Dutton believes that a particular challenge in this area will be scaling 'from a simple amino acid to a fully functional and complex protein.' 

Rachel Cooper