Polarized X-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin
Visible light can break the Fe-CO bond in Fe(II) carbonmonoxy-myoglobin (MbCO) giving an unligated product (Mb*) that is almost stable at T < 30 K. Fe K-edge polarized X-ray absorption spectra (P-XAS) of the photoproduct (T = 20 K) of an oriented single crystal (0.2 x 0.2 x 0.3 mm) of sperm whale...
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ftunicattolicair:oai:publicatt.unicatt.it:10807/11820 2024-04-21T08:12:21+00:00 Polarized X-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin Arcovito, Alessandro Della Longa, S Arcovito, Alessandro Vallone, B Castellano, A Kahn, R Vicat, J Soldo, Y Hazemann, J. 1999 http://hdl.handle.net/10807/11820 https://doi.org/10.1107/S0909049599010845 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000083648800011 volume:6 issue:Marzo firstpage:1138 lastpage:1147 numberofpages:10 issueyear:1999 journal:JOURNAL OF SYNCHROTRON RADIATION http://hdl.handle.net/10807/11820 doi:10.1107/S0909049599010845 http://dx.medra.org/10.1107/S0909049599010845 XANES Low temperature photoproduct Settore BIO/10 - BIOCHIMICA info:eu-repo/semantics/article 1999 ftunicattolicair https://doi.org/10.1107/S0909049599010845 2024-03-27T18:00:42Z Visible light can break the Fe-CO bond in Fe(II) carbonmonoxy-myoglobin (MbCO) giving an unligated product (Mb*) that is almost stable at T < 30 K. Fe K-edge polarized X-ray absorption spectra (P-XAS) of the photoproduct (T = 20 K) of an oriented single crystal (0.2 x 0.2 x 0.3 mm) of sperm whale MbCO (space group P2(1)) have been collected. By rotating the crystal the X-ray photon polarization vector has been oriented almost parallel (with an angle (alpha = 23 degrees) or perpendicular (alpha = 86 degrees) to the heme normal of each myoglobin molecule. The crystal was continuously illuminated by a white-light source during the data collection. The polarized data give novel information on the Fe-heme electronic/structural rearrangement following photolysis. The XANES (X-ray absorption near-edge structure) spectrum polarized in the direction close to the Fe-CO bond changes dramatically after photolysis, exhibiting a shift of similar to 2 eV, due to electronic relaxation of empty states of p(z) symmetry, while more subtle changes are observed in the spectrum polarized along the heme plane, sensitive to the heme-plane geometry. Changes in the pre-edge region can be interpreted to provide insight into the electronic structure of the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO) in the MbCO --> Mb* photochemical reaction at low temperature. Article in Journal/Newspaper Sperm whale Università Cattolica del Sacro Cuore: PubliCatt Journal of Synchrotron Radiation 6 6 1138 1147 |
institution |
Open Polar |
collection |
Università Cattolica del Sacro Cuore: PubliCatt |
op_collection_id |
ftunicattolicair |
language |
English |
topic |
XANES Low temperature photoproduct Settore BIO/10 - BIOCHIMICA |
spellingShingle |
XANES Low temperature photoproduct Settore BIO/10 - BIOCHIMICA Arcovito, Alessandro Polarized X-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin |
topic_facet |
XANES Low temperature photoproduct Settore BIO/10 - BIOCHIMICA |
description |
Visible light can break the Fe-CO bond in Fe(II) carbonmonoxy-myoglobin (MbCO) giving an unligated product (Mb*) that is almost stable at T < 30 K. Fe K-edge polarized X-ray absorption spectra (P-XAS) of the photoproduct (T = 20 K) of an oriented single crystal (0.2 x 0.2 x 0.3 mm) of sperm whale MbCO (space group P2(1)) have been collected. By rotating the crystal the X-ray photon polarization vector has been oriented almost parallel (with an angle (alpha = 23 degrees) or perpendicular (alpha = 86 degrees) to the heme normal of each myoglobin molecule. The crystal was continuously illuminated by a white-light source during the data collection. The polarized data give novel information on the Fe-heme electronic/structural rearrangement following photolysis. The XANES (X-ray absorption near-edge structure) spectrum polarized in the direction close to the Fe-CO bond changes dramatically after photolysis, exhibiting a shift of similar to 2 eV, due to electronic relaxation of empty states of p(z) symmetry, while more subtle changes are observed in the spectrum polarized along the heme plane, sensitive to the heme-plane geometry. Changes in the pre-edge region can be interpreted to provide insight into the electronic structure of the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO) in the MbCO --> Mb* photochemical reaction at low temperature. |
author2 |
Della Longa, S Arcovito, Alessandro Vallone, B Castellano, A Kahn, R Vicat, J Soldo, Y Hazemann, J. |
format |
Article in Journal/Newspaper |
author |
Arcovito, Alessandro |
author_facet |
Arcovito, Alessandro |
author_sort |
Arcovito, Alessandro |
title |
Polarized X-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin |
title_short |
Polarized X-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin |
title_full |
Polarized X-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin |
title_fullStr |
Polarized X-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin |
title_full_unstemmed |
Polarized X-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin |
title_sort |
polarized x-ray absorption spectroscopy of the low-temperature photoproduct of carbonmonoxy-myoglobin |
publishDate |
1999 |
url |
http://hdl.handle.net/10807/11820 https://doi.org/10.1107/S0909049599010845 |
genre |
Sperm whale |
genre_facet |
Sperm whale |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000083648800011 volume:6 issue:Marzo firstpage:1138 lastpage:1147 numberofpages:10 issueyear:1999 journal:JOURNAL OF SYNCHROTRON RADIATION http://hdl.handle.net/10807/11820 doi:10.1107/S0909049599010845 http://dx.medra.org/10.1107/S0909049599010845 |
op_doi |
https://doi.org/10.1107/S0909049599010845 |
container_title |
Journal of Synchrotron Radiation |
container_volume |
6 |
container_issue |
6 |
container_start_page |
1138 |
op_container_end_page |
1147 |
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1796932388818780160 |