Sensitivity-enhanced magnetic resonance reveals hydrogen intermediates during active [Fe]-hydrogenase catalysis

Abstract

AbstractMolecular hydrogen (H2) is considered an eco-friendly future energy-carrier and an alternative to fossil fuel1and thus, major efforts are directed towards identifying efficient and economical hydrogen catalysts.2,3Efficient hydrogen catalysis is used by many microorganisms, some of them producing H2from organic materials and others consuming it.4-6To metabolize H2, these microorganisms use enzymes called hydrogenases.7,8For the future development of efficient catalysts a detailed analysis of the catalytic mechanisms of such hydrogenases is required and existing analytical techniques could not provide a full understanding.9Consequently, new analytical technologies are of utmost importance to unravel natures’ blueprints for highly efficient hydrogen catalysts. Here, we introduce signal-enhanced or hyperpolarized, nuclear magnetic resonance (NMR) to study hydrogenases under turnover conditions. So far undiscovered hydrogen species of the catalytic cycle of [Fe]-hydrogenases, are revealed and thus, extend the knowledge regarding this class of enzymes. These findings pave new pathways for the exploration of novel hydrogen metabolismsin vivo. We furthermore envision that the results contribute to the rational design of future catalysts to solve energy challenges of our society.