Heme protein fluorescence versus pressure.
Fluorescence spectra of several ferric heme proteins have been measured vs. pressure to 6,000 bars. Sperm whale myoglobin (SW Mb), Aplysia myoglobin, leghemoglobin (Lb), and cytochrome P450 all show excitation and emission spectra characteristic of tryptophan in proteins with peak emission at 330-34...
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ftpubmed:oai:pubmedcentral.nih.gov:1329509 2023-05-15T18:26:48+02:00 Heme protein fluorescence versus pressure. Marden, M C Hui Bon Hoa, G Stetzkowski-Marden, F 1986-03 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1329509 http://www.ncbi.nlm.nih.gov/pubmed/3697474 en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1329509 http://www.ncbi.nlm.nih.gov/pubmed/3697474 Research Article Text 1986 ftpubmed 2013-08-30T19:18:08Z Fluorescence spectra of several ferric heme proteins have been measured vs. pressure to 6,000 bars. Sperm whale myoglobin (SW Mb), Aplysia myoglobin, leghemoglobin (Lb), and cytochrome P450 all show excitation and emission spectra characteristic of tryptophan in proteins with peak emission at 330-340 nm. At one bar, the fluorescence is weak due to energy transfer to the heme group, which makes the yield a sensitive probe of protein unfolding at high pressure. After an initial decrease of a few percent per kbar, the protein shows a large increase in fluorescence at high pressure. The increase is pH dependent and the results indicate that several high pressure states occur. For SW Mb at 15 degrees C an increase of a factor of 20 occurs with midpoint at 2,000 bars at pH 5 and is only partially reversible, while the increase at pH 7 occurs at 4,000 bars and is only half as large and is completely reversible. Aplysia Mb and Lb show a similar effect, but unfold at a higher pressure than SW Mb. P450 also shows a transition to a state of higher fluorescence, but the transition in this case is irreversible as a stable form, P420, is formed. The fluorescence intensity measurements permit an estimation of the increase in the TRY-heme distance in the high pressure state. Text Sperm whale PubMed Central (PMC) |
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Research Article Marden, M C Hui Bon Hoa, G Stetzkowski-Marden, F Heme protein fluorescence versus pressure. |
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Research Article |
description |
Fluorescence spectra of several ferric heme proteins have been measured vs. pressure to 6,000 bars. Sperm whale myoglobin (SW Mb), Aplysia myoglobin, leghemoglobin (Lb), and cytochrome P450 all show excitation and emission spectra characteristic of tryptophan in proteins with peak emission at 330-340 nm. At one bar, the fluorescence is weak due to energy transfer to the heme group, which makes the yield a sensitive probe of protein unfolding at high pressure. After an initial decrease of a few percent per kbar, the protein shows a large increase in fluorescence at high pressure. The increase is pH dependent and the results indicate that several high pressure states occur. For SW Mb at 15 degrees C an increase of a factor of 20 occurs with midpoint at 2,000 bars at pH 5 and is only partially reversible, while the increase at pH 7 occurs at 4,000 bars and is only half as large and is completely reversible. Aplysia Mb and Lb show a similar effect, but unfold at a higher pressure than SW Mb. P450 also shows a transition to a state of higher fluorescence, but the transition in this case is irreversible as a stable form, P420, is formed. The fluorescence intensity measurements permit an estimation of the increase in the TRY-heme distance in the high pressure state. |
format |
Text |
author |
Marden, M C Hui Bon Hoa, G Stetzkowski-Marden, F |
author_facet |
Marden, M C Hui Bon Hoa, G Stetzkowski-Marden, F |
author_sort |
Marden, M C |
title |
Heme protein fluorescence versus pressure. |
title_short |
Heme protein fluorescence versus pressure. |
title_full |
Heme protein fluorescence versus pressure. |
title_fullStr |
Heme protein fluorescence versus pressure. |
title_full_unstemmed |
Heme protein fluorescence versus pressure. |
title_sort |
heme protein fluorescence versus pressure. |
publishDate |
1986 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1329509 http://www.ncbi.nlm.nih.gov/pubmed/3697474 |
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Sperm whale |
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Sperm whale |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1329509 http://www.ncbi.nlm.nih.gov/pubmed/3697474 |
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1766208768840826880 |