Cluster-Dependent Charge-Transfer Dynamics in Iron-Sulfur Proteins
| Autor: | Francis E. Jenney, Shu-Hao Liou, David B. Goodin, Nimesh Khadka, Lance C. Seefeldt, Michael W. W. Adams, Ziliang Mao, Stephen P. Cramer, Delmar S. Larsen |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Iron-Sulfur Proteins
Models Molecular Biochemistry & Molecular Biology Protein Conformation Medical Biochemistry and Metabolomics 010402 general chemistry 01 natural sciences Biochemistry Chemical reaction Article Electron Transport Medicinal and Biomolecular Chemistry Electron transfer Protein structure Bacterial Proteins Models Rubredoxin Catalytic Domain Cluster (physics) Azotobacter vinelandii biology Bacteria 010405 organic chemistry Chemistry Pseudomonas putida Rubredoxins Relaxation (NMR) Molecular biology.organism_classification Electron transport chain 0104 chemical sciences Pyrococcus furiosus Chemical physics Ferredoxins Biochemistry and Cell Biology Oxidoreductases Oxidation-Reduction |
| Zdroj: | Biochemistry, vol 57, iss 6 Biochemistry |
| ISSN: | 1520-4995 |
| Popis: | Photo-induced charge-transfer dynamics and the influence of cluster size on the dynamics were investigated using five iron-sulfur clusters: the 1Fe-4S cluster in Pyrococcus furiosus rubredoxin, the 2Fe-2S cluster in Pseudomonas putida putidaredoxin, the 4Fe-4S cluster in nitrogenase iron protein, and the 8Fe-7S P-cluster and the 7Fe-9S-1Mo FeMo cofactor in nitrogenase MoFe protein. Laser excitation promotes the iron-sulfur clusters to excited electronic states that relax to lower states. The electronic relaxation lifetimes of the 1Fe-4S, the 8Fe-7S, and the 7Fe-9S-1Mo clusters are in the picoseconds timescale, although the dynamics of the MoFe protein is a mixture of the dynamics of the later two clusters. The lifetimes of the 2Fe-2S and the 4Fe-4S clusters, however, extend to several nanoseconds. A competition between reorganization energies and density of electronic states (thus electronic coupling between states) mediates the charge-transfer lifetimes, with the 2Fe-2S cluster of Pdx and the 4Fe-4S cluster of Fe protein lying at the optimum leading to them having significantly longer lifetimes. Their long lifetimes make them the optimal candidates for long-range electron transfer and as external photosensitizers for other photo-activated chemical reactions like solar hydrogen production. Potential electron-transfer and hole-transfer pathways are proposed that possibly facilitate these charge transfers. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|