Observing heme doming in myoglobin with femtosecond X-ray absorption spectroscopy
We report time-resolved X-ray absorption measurements after photolysis of carbonmonoxy myoglobin performed at the LCLS X-ray free electron laser with nearly 100 fs (FWHM) time resolution. Data at the Fe K-edge reveal that the photoinduced structural changes at the heme occur in two steps, with a faster (~70 fs) relaxation preceding a slower (~400 fs) one. We tentatively attribute the first relaxation to a structural rearrangement induced by photolysis involving essentially only the heme chromophore and the second relaxation to a residual Fe motion out of the heme plane that is coupled to the displacement of myoglobin F-helix.
- Univ. of Palermo, Palermo (Italy)
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- CNRS - Institut de Biologie Structurale, Grenoble 38044, France
- Univ. of Rennes, Rennes (France)
- Publication Date:
- OSTI Identifier:
- Accepted Manuscript
- Journal Name:
- Structural Dynamics
- Additional Journal Information:
- Journal Volume: 2; Journal Issue: 4; Journal ID: ISSN 2329-7778
- American Crystallographic Association/AIP
- Research Org:
- SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
- Sponsoring Org:
- USDOE Office of Science (SC)
- Country of Publication:
- United States
- 63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
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