Theoretical studies of [FeFe]-hydrogenase: structure and infrared spectra of synthetic models.
First-principles density functional theory calculations of synthetic models of [FeFe]-hydrogenase are used to show that the theoretical methods reproduce observed structures and infrared spectra to high accuracy. The accuracy is demonstrated for synthetic Fe(I)Fe(I) models ([(mu-PDT)Fe2(CO)6] and [(CN)(CO)2(mu-PDT)Fe2(CO)2(CN)]2-), for which we show that their infrared spectra are sensitive to the geometric arrangement of their CO/CN ligands and can be used in conjunction with quantum-mechanical total energies to predict the correct ligand geometry. We then analyze and predict the structure of mixed-valence Fe(II)Fe(I) models ([(mu-MeSCH2C(Me)(CH2S)2)Fe2(CO)4(CN)2]x-). These capabilities promise to distinguish among the various structural isomers of the enzyme's active site which are consistent with the limited accuracy of the X-ray observations.
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
Silviu
S
Zilberman
Edward I
EI
Stiefel
Morrel H
MH
Cohen
Roberto
R
Car
D003198:Computer Simulation; D006864:Hydrogenase / Q000737:chemistry*; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D007536:Isomerism; D008958:Models, Molecular; D010084:Oxidation-Reduction; D013055:Spectrophotometry, Infrared
D007506:Iron-Sulfur Proteins; C118830:iron hydrogenase; D006864:Hydrogenase