Molecular Pendulum Boosts Hydrogen Production Efficiency - Mirage News

How an inhibitor can help us understand biocatalystsZinc occurs naturally in many biocatalysts, where it is needed for the reaction mechanism. This metal ion binds to reactive groups of certain molecular components—the amino acids— of the enzyme. "Yet through this same bond, zinc can block biocatalysts," explains Dr. Jifu Duan, first author of the current study. "It can also bind non-specifically to sites required for proton binding. "Researchers at Ruhr University Bochum have examined how zinc affects the production of hydrogen by [FeFe]-hydrogenases—and made an interesting discovery. "Although we were able to see in crystal structures that zinc binds to various sites of the [FeFe]-hydrogenases, the interaction at only one very specific location resulted in inhibition," says Duan. Notably, this point is in the direct vicinity of the previously known proton transport pathway of the hydrogenases. Zinc blocks a proton-transporting pendulumThe team around Duan and Professor Thomas Happe was able to demonstrate that the binding of zinc and other metal ions blocks very specific amino acids, namely two histidines on the surface of [FeFe]-hydrogenases.