title: Analysis of differences in oxygen sensitivity of Fe-S clusters.
abstract: Many but not all iron-sulphur clusters in metalloproteins are known to be sensitive to molecular oxygen with dramatic consequences for their biological function. We performed a systematic quantum chemical investigation that sheds light on the differences in oxygen sensitivity depending on charge and spin states of these clusters as well as on their spatial fixation by the enzyme's scaffold. We find that significant structural distortions are required to bind O2 exothermically to [Fe2S2] and [Fe3S4] clusters, while only small conformational changes allow for the thermodynamically favorable coordination of molecular oxygen to [Fe4S4] cubanes and [Fe4S3] clusters.
authors: ETH Zurich, Laboratorium für Physikalische Chemie, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland.
authors: Marta K
authors: MK
authors: Bruska
authors: Martin T
authors: MT
authors: Stiebritz
authors: Markus
authors: M
authors: Reiher
mesh_terms: D002621:Chemistry / Q000379:methods; D004798:Enzymes / Q000737:chemistry; D006860:Hydrogen Bonding; D007501:Iron / Q000737:chemistry; D007506:Iron-Sulfur Proteins / Q000737:chemistry*; D008667:Metalloproteins / Q000737:chemistry; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D013057:Spectrum Analysis / Q000379:methods; D013455:Sulfur / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics
chemical_list: D004798:Enzymes; D007506:Iron-Sulfur Proteins; D008667:Metalloproteins; D013455:Sulfur; D007501:Iron; D010100:Oxygen