The Laser-Induced Potential Jump: A Method for Rapid Electron Injection into Oxidoreductase Enzymes.

Oxidoreductase enzymes often perform technologically useful chemical transformations using abundant metal cofactors with high efficiency under ambient conditions. The understanding of the catalytic mechanism of these enzymes is, however, highly dependent on the availability of well-characterized and optimized time-resolved analytical techniques. We have developed an approach for rapidly injecting electrons into a catalytic system using a photoactivated nanomaterial in combination with a range of redox mediators to produce a potential jump in solution, which then initiates turnover via electron transfer (ET) to the catalyst.

Engineering Proton Transfer in Photosynthetic Oxygen Evolution: Chloride, Nitrate, and Trehalose Reorganize a Hydrogen-Bonding Network.

Photosystem II oxidizes water at a MnCaO cluster. Oxygen evolution is accompanied by proton release through a 35 Å hydrogen-bonding network to the lumen. The mechanism of this proton-transfer reaction is not known, but the reaction is dependent on chloride.