Unravelling enzymatic hydrogen production mechanisms with ultrafast 2D-IR spectroscopy
Lead Research Organisation:
University of York
Department Name: Chemistry
Abstract
The hydrogenases are families of metalloenzymes that efficiently catalyse the reversible cleavage of H2 into protons and electrons and so offer ideal prototype catalysts for sustainable energy generation involving H2. Before we can develop technological materials based upon the hydrogenases however, a detailed understanding of the mechanism of H2 production and usage is required. This multidisciplinary project will combine ultrafast 2D-IR spectroscopy (Hunt) with electrochemical and biochemical methods (Parkin) to understand structural changes and the role of dynamic processes in the action of these important enzymes.
2D-IR is a new ultrafast laser spectroscopy method that spreads the IR spectrum of a molecule over a second frequency axis [1]. This multidimensionality allows access to a wealth of new spectral information but the most powerful aspect of 2D-IR is the ability to determine molecular structure and changes in that structure with a time resolution of 100 fs (10-13 s). This opens up the possibility of observing reaction steps, solvent motion or H-bond vibrations that are central to the hydrogenase mechanism in real time. This is highly complementary to the insight into ultrafast electron movement in hydrogenases which can has been obtained in the Parkin group using Fourier transform large amplitude alternating current voltammetry [2].
Although synthetic models of the hydrogenases have been studied with 2D-IR [3,4], this collaboration offers the unique opportunity to compare these results with the full enzyme systems for the first time. By studying a range of site mutations and using electrochemical methods to prepare catalytic intermediates we will use 2D-IR to understand the way in which the protein scaffold interacts with the active site to influence or control the enzyme mechanism. This is a particularly important issue since biomimetic model compounds lacking the protein scaffold show very low catalytic efficiency, emphasising its importance [4], but the precise molecular function that it plays in the enzyme cycle is unknown.
(1) Hunt, N. T. Chem Soc Rev 2009, 38, 1837.
(2) Adamson, H.; Robinson, M.; Wright, J. J.; Flanagan, L. A.; Walton, J.; Elton, D.; Gavaghan, D. J.; Bond, A. M.; Roessler, M. M.; Parkin, A. Journal of the American Chemical Society 2017, 139, 10677.
(3) Fritzsch, R.; Brady, O.; Adair, E.; Wright, J. A.; Pickett, C. J.; Hunt, N. T. Journal of Physical Chemistry Letters 2016, 7, 2838.
(4) Frederix, P. W. J. M.; Adamczyk, K.; Wright, J. A.; Tuttle, T.; Ulijn, R. V.; Pickett, C. J.; Hunt, N. T. Organometallics 2014, 33, 5888.
2D-IR is a new ultrafast laser spectroscopy method that spreads the IR spectrum of a molecule over a second frequency axis [1]. This multidimensionality allows access to a wealth of new spectral information but the most powerful aspect of 2D-IR is the ability to determine molecular structure and changes in that structure with a time resolution of 100 fs (10-13 s). This opens up the possibility of observing reaction steps, solvent motion or H-bond vibrations that are central to the hydrogenase mechanism in real time. This is highly complementary to the insight into ultrafast electron movement in hydrogenases which can has been obtained in the Parkin group using Fourier transform large amplitude alternating current voltammetry [2].
Although synthetic models of the hydrogenases have been studied with 2D-IR [3,4], this collaboration offers the unique opportunity to compare these results with the full enzyme systems for the first time. By studying a range of site mutations and using electrochemical methods to prepare catalytic intermediates we will use 2D-IR to understand the way in which the protein scaffold interacts with the active site to influence or control the enzyme mechanism. This is a particularly important issue since biomimetic model compounds lacking the protein scaffold show very low catalytic efficiency, emphasising its importance [4], but the precise molecular function that it plays in the enzyme cycle is unknown.
(1) Hunt, N. T. Chem Soc Rev 2009, 38, 1837.
(2) Adamson, H.; Robinson, M.; Wright, J. J.; Flanagan, L. A.; Walton, J.; Elton, D.; Gavaghan, D. J.; Bond, A. M.; Roessler, M. M.; Parkin, A. Journal of the American Chemical Society 2017, 139, 10677.
(3) Fritzsch, R.; Brady, O.; Adair, E.; Wright, J. A.; Pickett, C. J.; Hunt, N. T. Journal of Physical Chemistry Letters 2016, 7, 2838.
(4) Frederix, P. W. J. M.; Adamczyk, K.; Wright, J. A.; Tuttle, T.; Ulijn, R. V.; Pickett, C. J.; Hunt, N. T. Organometallics 2014, 33, 5888.