Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses.
We have measured spectral and kinetic differences in protoheme, sperm whale or horse heart myoglobin and human hemoglobin following photodissociation induced by optical pulses of 80 fs duration. Full ligation was performed with oxygen or carbon monoxide. Femtosecond kinetics and transient difference...
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ftpubmed:oai:pubmedcentral.nih.gov:555364 2023-05-15T18:26:45+02:00 Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. Martin, J L Migus, A Poyart, C Lecarpentier, Y Astier, R Antonetti, A 1983 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC555364 http://www.ncbi.nlm.nih.gov/pubmed/6641703 en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC555364 http://www.ncbi.nlm.nih.gov/pubmed/6641703 Research Article Text 1983 ftpubmed 2013-08-30T04:32:34Z We have measured spectral and kinetic differences in protoheme, sperm whale or horse heart myoglobin and human hemoglobin following photodissociation induced by optical pulses of 80 fs duration. Full ligation was performed with oxygen or carbon monoxide. Femtosecond kinetics and transient difference spectra revealed the appearance of a deoxy species with tau approximately equal to 250-300 fs. The transient deoxy species in myoglobin and hemoglobin evidenced a 3-4 nm red shift of their delta A spectra compared with the equilibrium delta A spectrum. This shift was not observed after photodissociation of the carbon monoxide liganded protoheme. We proposed that the 250 fs time constant corresponding to the appearance of the deoxy-like species is related to the displacement of the ferrous iron out of the heme plane. Consequently, the small red shift of the delta A spectra observed in photodissociated hemoproteins may be tentatively attributed to changes in the vibrational modes of either the proximal histidine-Fe2+ bond and/or of the N4 porph-Fe-N epsilon His (F8) bent. Text Sperm whale PubMed Central (PMC) |
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Research Article Martin, J L Migus, A Poyart, C Lecarpentier, Y Astier, R Antonetti, A Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. |
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Research Article |
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We have measured spectral and kinetic differences in protoheme, sperm whale or horse heart myoglobin and human hemoglobin following photodissociation induced by optical pulses of 80 fs duration. Full ligation was performed with oxygen or carbon monoxide. Femtosecond kinetics and transient difference spectra revealed the appearance of a deoxy species with tau approximately equal to 250-300 fs. The transient deoxy species in myoglobin and hemoglobin evidenced a 3-4 nm red shift of their delta A spectra compared with the equilibrium delta A spectrum. This shift was not observed after photodissociation of the carbon monoxide liganded protoheme. We proposed that the 250 fs time constant corresponding to the appearance of the deoxy-like species is related to the displacement of the ferrous iron out of the heme plane. Consequently, the small red shift of the delta A spectra observed in photodissociated hemoproteins may be tentatively attributed to changes in the vibrational modes of either the proximal histidine-Fe2+ bond and/or of the N4 porph-Fe-N epsilon His (F8) bent. |
format |
Text |
author |
Martin, J L Migus, A Poyart, C Lecarpentier, Y Astier, R Antonetti, A |
author_facet |
Martin, J L Migus, A Poyart, C Lecarpentier, Y Astier, R Antonetti, A |
author_sort |
Martin, J L |
title |
Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. |
title_short |
Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. |
title_full |
Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. |
title_fullStr |
Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. |
title_full_unstemmed |
Spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. |
title_sort |
spectral evidence for sub-picosecond iron displacement after ligand detachment from hemoproteins by femtosecond light pulses. |
publishDate |
1983 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC555364 http://www.ncbi.nlm.nih.gov/pubmed/6641703 |
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Sperm whale |
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Sperm whale |
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC555364 http://www.ncbi.nlm.nih.gov/pubmed/6641703 |
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1766208722728648704 |