Gas Diffusion in Hydrogenase

The native structure of hydrogenase from the bacterium Clostridium acetobutylicum is being truncated with the goal of simplifying the enzyme for biotechnological catalysis. The full structure of the closely related C. pasteurianum hydrogenase is shown here, with the truncation in green and hypothetical variant structure in blue. Catalytic and accessory electron transfer clusters are shown as spheres.

Our Challenge

A collaborative effort among NREL's Scientific Computing Center (SCC) and Basic Sciences Centers, the Theoretical and Computational Biophysics Group at the University of Illinois at Urbana-Champaign (TCBG-UIUC), and Arizona State University seeks to harvest Nature's bounty in the form of [FeFe] hydrogenase enzymes for the design of next-generation H₂ production catalysts. Unlike energy-intensive commercial processes or chemical catalysts derived from precious metals, biology has evolved to exploit limited energy and abundant materials to produce hydrogen in a wide variety of ecological contexts.

Our Results

SCC is addressing the biotechnological limitations of [FeFe] hydrogenase enzymes—including competition for cellular redox partners, oxygen sensitivity, and interfacial electron transfer (ET)—through modeling of protein/protein interactions, structure-function relationships, intramolecular gas diffusion, and metallocluster electronic structure. A combination of rigid-body docking and stochastic dynamics, classical mechanical atomistic dynamics, and Kohn-Sham density functional theory is being used to design enzyme variants with increased O₂ resistance, enhanced intracellular electrophilicity, and favorable ET kinetics and protein stability in integrated electrochemical-biological hybrid systems.

Our Results

Work with TCBG-UIUC regarding the design of O₂-tolerant hydrogenases has recently received national exposure, as seen in the following links: News Bureau (University of Illinois at Urbana-Champaign), PhysOrg.com, and EurekAlert.org.

Printable Version