Near infrared transient absorption spectra of photolyzed myoglobin at low temperatures
We have measured the transient absorption spectrum of photolyzed sperm whale carboxymyoglobin as a function of temperature and time after photolysis. Our measurements extend from 60K to 220K and from three microseconds to thirty seconds. We see an absorption band near 758 nm which is known as band V...
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ftunivillidea:oai:www.ideals.illinois.edu:2142/25311 2023-05-15T18:26:43+02:00 Near infrared transient absorption spectra of photolyzed myoglobin at low temperatures Bowne, Samuel Franklin Frauenfelder, Hans 1984 http://hdl.handle.net/2142/25311 unknown http://hdl.handle.net/2142/25311 824272 1984 Samuel Franklin Bowne transient absorption spectrum photolyzed carboxymyoglobin band shifts text 1984 ftunivillidea 2016-03-19T23:29:05Z We have measured the transient absorption spectrum of photolyzed sperm whale carboxymyoglobin as a function of temperature and time after photolysis. Our measurements extend from 60K to 220K and from three microseconds to thirty seconds. We see an absorption band near 758 nm which is known as band VIII. Three microseconds after photolysis at 60K, the center of band VIII is 766 nm, red-shifted from the peak seen in deoxy myoglobin at this temperature. Band VIII shifts with time towards the deoxy value with a nonexponential time course. We conclude that this shift is caused by unrelaxed degrees of freedom in the protein at these temperatures. We present a model in which each protein has several "blocking residues" which relax following photolysis by surmounting enthalpy barriers which range from ten to fifty kJ/mol. These motions do not affect the rate of ligand rebinding. Text Sperm whale University of Illinois at Urbana-Champaign: IDEALS (Illinois Digital Environment for Access to Learning and Scholarship) |
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University of Illinois at Urbana-Champaign: IDEALS (Illinois Digital Environment for Access to Learning and Scholarship) |
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transient absorption spectrum photolyzed carboxymyoglobin band shifts |
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transient absorption spectrum photolyzed carboxymyoglobin band shifts Bowne, Samuel Franklin Near infrared transient absorption spectra of photolyzed myoglobin at low temperatures |
topic_facet |
transient absorption spectrum photolyzed carboxymyoglobin band shifts |
description |
We have measured the transient absorption spectrum of photolyzed sperm whale carboxymyoglobin as a function of temperature and time after photolysis. Our measurements extend from 60K to 220K and from three microseconds to thirty seconds. We see an absorption band near 758 nm which is known as band VIII. Three microseconds after photolysis at 60K, the center of band VIII is 766 nm, red-shifted from the peak seen in deoxy myoglobin at this temperature. Band VIII shifts with time towards the deoxy value with a nonexponential time course. We conclude that this shift is caused by unrelaxed degrees of freedom in the protein at these temperatures. We present a model in which each protein has several "blocking residues" which relax following photolysis by surmounting enthalpy barriers which range from ten to fifty kJ/mol. These motions do not affect the rate of ligand rebinding. |
author2 |
Frauenfelder, Hans |
format |
Text |
author |
Bowne, Samuel Franklin |
author_facet |
Bowne, Samuel Franklin |
author_sort |
Bowne, Samuel Franklin |
title |
Near infrared transient absorption spectra of photolyzed myoglobin at low temperatures |
title_short |
Near infrared transient absorption spectra of photolyzed myoglobin at low temperatures |
title_full |
Near infrared transient absorption spectra of photolyzed myoglobin at low temperatures |
title_fullStr |
Near infrared transient absorption spectra of photolyzed myoglobin at low temperatures |
title_full_unstemmed |
Near infrared transient absorption spectra of photolyzed myoglobin at low temperatures |
title_sort |
near infrared transient absorption spectra of photolyzed myoglobin at low temperatures |
publishDate |
1984 |
url |
http://hdl.handle.net/2142/25311 |
genre |
Sperm whale |
genre_facet |
Sperm whale |
op_relation |
http://hdl.handle.net/2142/25311 824272 |
op_rights |
1984 Samuel Franklin Bowne |
_version_ |
1766208697386663936 |