Researchers at the Beckman Institute for Advanced Science and Technology at the University of Illinois at Urbana-Champaign have opened a window by way of computer simulation that lets them see how and where hydrogen and oxygen travel to reach and exit an enzyme's catalyst site -- the H cluster -- where the hydrogen is converted into energy.
The Illinois scientists and three colleagues from the National Renewable Energy Laboratory in Golden, Colo., detailed their findings in the September issue of the journal Structure. What they found could help solve a long-standing economics problem. Because oxygen permanently binds to hydrogen in the H cluster, the production of hydrogen gas is halted. As a result, the supply is short-lived. Numerous microorganisms have enzymes known as hydrogenases that simply use sunlight and water to generate hydrogen-based energy.
"Understanding how oxygen reaches the active site will provide insight into how hydrogenase's oxygen tolerance can be increased through protein engineering, and, in turn, make hydrogenase an economical source of hydrogen fuel," said Klaus Schulten, Swanlund Professor of Physics at Illinois and leader of the Beckman's Theoretical Biophysics Group.
Using computer modeling developed in Schulten's lab -- Nanoscale Molecular Dynamics (NAMD) and Visual Molecular Dynamics (VMD) -- physics doctoral student Jordi Cohen created an all-atom simulation model based on the crystal structure of hydrogenase CpI from Clostridium pasteurianum.
This model allowed Cohen to visualize and track how oxygen and hydrogen travel to the hydrogenase's catalytic site, wher
Contact: Jim Barlow, Life Sciences Editor
University of Illinois at Urbana-Champaign