Structure and vibrational dynamics of model compounds of the [FeFe]-hydrogenase enzyme system via ultrafast two-dimensional infrared spectroscopy.
Ultrafast two-dimensional infrared (2D) spectroscopy has been applied to study the structure and vibrational dynamics of (mu-S(CH2)3S)Fe2(CO)6, a model compound of the active site of the [FeFe]-hydrogenase enzyme system. Comparison of 2D-IR spectra of (mu-S(CH2)3S)Fe2(CO)6 with density functional theory calculations has determined that the solution-phase structure of this molecule is similar to that observed in the crystalline phase and in good agreement with gas-phase simulations. In addition, vibrational coupling and rapid (<5 ps) solvent-mediated equilibration of energy between vibrationally excited states of the carbonyl ligands of the di-iron-based active site model are observed prior to slower (approximately 100 ps) relaxation to the ground state. These dynamics are shown to be solvent-dependent and form a basis for the future determination of the vibrational interactions between active site and protein.
Stewart
A I
AI
Department of Physics, University of Strathclyde, SUPA, 107 Rottenrow East, Glasgow G4 0NG, UK.
Clark
I P
IP
Towrie
M
M
Ibrahim
S K
SK
Parker
A W
AW
Pickett
C J
CJ
Hunt
N T
NT
D006864:Hydrogenase / Q000737:chemistry / Q000378:metabolism*; D007506:Iron-Sulfur Proteins / Q000737:chemistry / Q000378:metabolism*; D013055:Spectrophotometry, Infrared / Q000379:methods*
D007506:Iron-Sulfur Proteins; C118830:iron hydrogenase; D006864:Hydrogenase