Angew. Chem. Int. Ed. http://doi.org/f3mb4c (2016)
Cells generate energy by coupling a proton gradient across a phospholipid bilayer with a membrane-spanning ATP synthase enzyme. In an effort to mimic this process in an artificial environment, Marisela Vélez, Antonio De Lacey, Iván López-Montero and colleagues now show that ATP can be efficiently produced by using molecular hydrogen as a fuel.
The researchers, who are based at the Spanish National Research Council, the Universidad Complutense de Madrid and the Universidade Nova de Lisboa, designed a biomimetic system with a hydrogenase catalyst bound to a gold surface, on top of which is deposited a membrane bilayer containing ATP synthase. Under a small voltage bias, hydrogen from solution gets oxidized, thus forming a proton gradient across the phospholipid membrane. This gradient, which can be as large as 1 pH unit, drives the conversion of ADP to ATP by reaction with a phosphate ion from solution.
The system developed by Vélez and co-workers is reversible (where the ATP synthase generates a proton gradient by converting ATP to ADP and phosphate ions) and has a turnover rate around an order of magnitude higher than that found in analogous biomimetic systems that use other means, such as light, to create the proton gradient.