| Literature DB >> 33597529 |
Marco E Reinhard1,2, Michael W Mara3,4, Thomas Kroll2, Hyeongtaek Lim3, Ryan G Hadt3,5, Roberto Alonso-Mori6, Matthieu Chollet6, James M Glownia6, Silke Nelson6, Dimosthenis Sokaras2, Kristjan Kunnus1, Tim Brandt van Driel6, Robert W Hartsock1, Kasper S Kjaer1, Clemens Weninger6, Elisa Biasin1, Leland B Gee3, Keith O Hodgson2,3, Britt Hedman2, Uwe Bergmann1, Edward I Solomon7,8, Kelly J Gaffney9,10.
Abstract
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.Entities:
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Year: 2021 PMID： 33597529 PMCID： PMC7889893 DOI： 10.1038/s41467-021-21423-w
Source DB: PubMed Journal: Nat Commun ISSN： 2041-1723 Impact factor: 14.919