Understanding Metalloenzymes by Computational Nonlinear Infrared Spectroscopy - Insights into the Structure, Function, and Dynamics of Hydrogenases

• Applicant: Dr. Marius Horch
• Subject Area: Physical Chemistry of Molecules, Liquids and Interfaces, Biophysical Chemistry
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 577155897

Metalloenzymes are metal-containing proteins that catalyse biochemical reactions with high efficiency and specificity. Thus, they represent valuable targets for biotechnological application and bioinspired catalyst design, but their rational utilization requires a fundamental understanding of structure, function, and dynamics – especially with respect to reactive metal sites and their functionalization by the protein environment. Oxygen-tolerant [NiFe] hydrogenases catalyse the reversible cleavage of hydrogen (H2) and in many cases the reductive detoxification of oxygen (O2) at a protein-embedded nickel-iron centre containing biologically unusual carbon monoxide (CO) and cyanide (CN−) ligands. Due to these unique features and the potential of H2 as a clean fuel, O2-tolerant [NiFe] hydrogenases are technologically relevant model metalloenzymes for studying key principles of bioinorganic catalysis and H2/O2 activation. Utilizing CO and CN− ligands as site-elective and structurally sensitive infrared (IR) chromophores, IR spectroscopy has long been used as a key technique for studying the [NiFe] active sites of these enzymes. To overcome inherent limitations of conventional IR absorption experiments, the applicant has recently introduced ultrafast and two-dimensional (2D) IR techniques into hydrogenase research. While these nonlinear techniques yield otherwise inaccessible insights into structure and dynamics at unprecedented time resolution, their application is so-far limited by a lack of understanding regarding complex spectroscopic signatures and the information encoded in underlying signals and their time evolution. To exploit these advanced IR techniques to their full potential, we will therefore establish and utilize computational strategies for simulating IRpump-IRprobe and 2D-IR spectra of [NiFe] hydrogenases. In this respect, we will apply second-order vibrational perturbation theory and molecular dynamics simulations together with multiple (quantum-classical) hybrid schemes and further strategies for reducing computational cost to variably sized models of the catalytic [NiFe] site. This approach will (1) yield a fundamental understanding of nonlinear IR spectra of hydrogenases and the associated structural and dynamical properties, (2) allow distinguishing aspects that are defined by the local structure of the catalytic site from those that are dictated by the functional protein environment, (3) provide a general computational toolbox for studying the previous two aspects in metalloenzymes, and (4) draw a clear picture of the catalytic mechanism of hydrogenases that also integrates theoretical aspects beyond the computational-spectroscopy paradigm. In total, we expect this project to provide fundamental insights into the structure, function, and dynamics of hydrogenases and other metalloenzymes, thereby facilitating their rational utilization.

• DFG Programme: Research Grants