Short-lived metal-centered excited state initiates iron-methionine photodissociation in ferrous cytochrome c
| Autor: | Kristjan Kunnus, Hyeongtaek Lim, Thomas Kroll, Robert W. Hartsock, Dimosthenis Sokaras, Britt Hedman, Leland B. Gee, Kelly J. Gaffney, Silke Nelson, Clemens Weninger, James M. Glownia, Michael W. Mara, Ryan G. Hadt, Elisa Biasin, Tim Brandt van Driel, Uwe Bergmann, Edward I. Solomon, Marco Reinhard, Keith O. Hodgson, Matthieu Chollet, Kasper S. Kjær, Roberto Alonso-Mori |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
Hemeprotein Cytochrome Iron Chemical physics Science General Physics and Astronomy Heme Molecular Dynamics Simulation 010402 general chemistry Photochemistry 01 natural sciences Article General Biochemistry Genetics and Molecular Biology Dissociation (chemistry) Ferrous Electron Transport 03 medical and health sciences Electron transfer Methionine Biophysical chemistry Ferrous Compounds Photolysis Multidisciplinary biology Chemistry Cytochrome c Photodissociation Excited states Cytochromes c Spectrometry X-Ray Emission General Chemistry 0104 chemical sciences 030104 developmental biology Metals Excited state biology.protein sense organs |
| Zdroj: | Nature Communications, Vol 12, Iss 1, Pp 1-8 (2021) Nature Communications |
| ISSN: | 2041-1723 |
| Popis: | The dynamics of photodissociation and recombination in heme proteins represent an archetypical photochemical reaction widely used to understand the interplay between chemical dynamics and reaction environment. We report a study of the photodissociation mechanism for the Fe(II)-S bond between the heme iron and methionine sulfur of ferrous cytochrome c. This bond dissociation is an essential step in the conversion of cytochrome c from an electron transfer protein to a peroxidase enzyme. We use ultrafast X-ray solution scattering to follow the dynamics of Fe(II)-S bond dissociation and 1s3p (Kβ) X-ray emission spectroscopy to follow the dynamics of the iron charge and spin multiplicity during bond dissociation. From these measurements, we conclude that the formation of a triplet metal-centered excited state with anti-bonding Fe(II)-S interactions triggers the bond dissociation and precedes the formation of the metastable Fe high-spin quintet state. The dissociation mechanism of the heme axial ligand in heme proteins is not yet fully understood. The authors investigate the photodissociation dynamics of the bond between heme Fe and methionine S in ferrous cytochrome c using femtosecond time-resolved X-ray solution scattering and X-ray emission spectroscopy, simultaneously tracking electronic and nuclear structure changes. |
| Databáze: | OpenAIRE |
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