Ultrafast 2D-IR spectroscopy of [NiFe] hydrogenase from E. coli reveals the role of the protein scaffold in controlling the active site environment.

Autor:	Wrathall SLD; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk., Procacci B; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk., Horch M; Freie Universität Berlin, Department of Physics, Ultrafast Dynamics in Catalysis, Arnimallee 14, 14195 Berlin, Germany., Saxton E; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk., Furlan C; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk., Walton J; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk., Rippers Y; Freie Universität Berlin, Department of Physics, Ultrafast Dynamics in Catalysis, Arnimallee 14, 14195 Berlin, Germany., Blaza JN; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk., Greetham GM; STFC Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0QX, UK., Towrie M; STFC Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0QX, UK., Parker AW; STFC Central Laser Facility, Research Complex at Harwell, Rutherford Appleton Laboratory, Harwell Campus, Didcot, OX11 0QX, UK., Lynam J; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk., Parkin A; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk., Hunt NT; Department of Chemistry and York Biomedical Research Institute, University of York, York, YO10 5DD, UK. neil.hunt@york.ac.uk.
Jazyk:	angličtina
Zdroj:	Physical chemistry chemical physics : PCCP [Phys Chem Chem Phys] 2022 Oct 19; Vol. 24 (40), pp. 24767-24783. Date of Electronic Publication: 2022 Oct 19.
DOI:	10.1039/d2cp04188j
Abstrakt:	Ultrafast two-dimensional infrared (2D-IR) spectroscopy of Escherichia coli Hyd-1 ( Ec Hyd-1) reveals the structural and dynamic influence of the protein scaffold on the Fe(CO)(CN) 2 unit of the active site. Measurements on as-isolated Ec Hyd-1 probed a mixture of active site states including two, which we assign to Ni r -S I/II , that have not been previously observed in the E. coli enzyme. Explicit assignment of carbonyl (CO) and cyanide (CN) stretching bands to each state is enabled by 2D-IR. Energies of vibrational levels up to and including two-quantum vibrationally excited states of the CO and CN modes have been determined along with the associated vibrational relaxation dynamics. The carbonyl stretching mode potential is well described by a Morse function and couples weakly to the cyanide stretching vibrations. In contrast, the two CN stretching modes exhibit extremely strong coupling, leading to the observation of formally forbidden vibrational transitions in the 2D-IR spectra. We show that the vibrational relaxation times and structural dynamics of the CO and CN ligand stretching modes of the enzyme active site differ markedly from those of a model compound K[CpFe(CO)(CN) 2 ] in aqueous solution and conclude that the protein scaffold creates a unique biomolecular environment for the NiFe site that cannot be represented by analogy to simple models of solvation.
Databáze:	MEDLINE
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