Engineering the Electron Relay in [FeFe]-Hydrogenase Enhances Electrocatalytic H <sub>2</sub> Evolution
Ting-ing Lai, William K. Myers, S.B. Carr, Miguel A. Ramirez, Kylie A. Vincent, Simone Morra, Patricia Rodríguez‐Maciá
Abstract
High Resolution Image Download MS PowerPoint Slide H 2 is an ideal energy vector, but catalysts for its clean production from water are inefficient or expensive. [FeFe]-hydrogenases are the most active H 2 -converting catalysts in nature, using a unique organometallic active site finely tuned by the protein matrix. M3 type [FeFe]-hydrogenases from Clostridium pasteurianum and Clostridium acetobutylicum are exceptionally active for H 2 production, and less O 2 sensitive than most other types of [FeFe]-hydrogenases, making them attractive targets for biotechnology. However, they are more challenging to work with because of their large size and the number of iron–sulfur clusters. Here, the [FeFe]-hydrogenase from C. acetobutylicum was systematically engineered to truncate each iron–sulfur-containing region of the F-domain, yielding smaller and easier-to-produce catalytic systems. Detailed characterization revealed that these variants retain high electrocatalytic performance and other essential properties of the natural enzyme.