The Organometallic Active Site of [Fe]Hydrogenase: Models and Entatic States

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 100; no. 7; pp. 3683 - 3688
• Main Authors: Darensbourg, Marcetta Y., Lyon, Erica J., Zhao, Xuan, Georgakaki, Irene P.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 01-04-2003; National Acad Sciences; The National Academy of Sciences
• Series: Bioinorganic Chemistry Special Feature
• Subjects: Active sites; Atoms; Binding Sites; Biochemistry; Bioinorganic Chemistry Special Feature; Cyanides; Enzymes; Hydrogen - metabolism; Hydrogenase - chemistry; Hydrogenase - metabolism; Iron; Iron-Sulfur Proteins - chemistry; Iron-Sulfur Proteins - metabolism; Kinetics; Ligands; Models, Molecular; Organometallic Compounds - chemistry; Physical Sciences; Protein Structure, Secondary; Protons; Reactivity; Rotation
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.0536955100

The simple organometallic, (μ-S2)Fe2(CO)6, serves as a precursor to synthetic analogues of the chemically rudimentary iron-only hydrogenase enzyme active site. The fundamental properties of the (μ-SCH2CH2CH2S)[ Fe(CO)3]2 compound, including structural mobility and regioselectivity in cyanide/carbon monoxide substitution reactions, relate to the enzyme active site in the form of transition-state structures along reaction paths rather than ground-state structures. Even in the absence of protein-based active-site organization, the ground-state structural model complexes are shown to serve as hydrogenase enzyme reaction models, H2 uptake and H2 production, with the input of photo- or electrochemical energy, respectively.