Structural and functional analysis of the two haemoglobins of the Antarctic seabird Catharacta maccormicki
The amino‐acid sequence and the oxygen‐binding properties of the two haemoglobins of the Antarctic seabird south polar skua have been investigated. The two haemoglobins showed peculiar functional features, which were probably acquired to meet special needs in relation to the extreme environmental co...
Published in: | European Journal of Biochemistry |
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crwiley:10.1046/j.1432-1327.2000.01699.x 2024-06-02T07:58:30+00:00 Structural and functional analysis of the two haemoglobins of the Antarctic seabird Catharacta maccormicki Characterization of an additional phosphate binding site by molecular modelling Tamburrini, Maurizio Riccio, Antonio Romano, Maurizio Giardina, Bruno di Prisco, Guido 2000 http://dx.doi.org/10.1046/j.1432-1327.2000.01699.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1432-1327.2000.01699.x https://febs.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1432-1327.2000.01699.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor European Journal of Biochemistry volume 267, issue 19, page 6089-6098 ISSN 0014-2956 1432-1033 journal-article 2000 crwiley https://doi.org/10.1046/j.1432-1327.2000.01699.x 2024-05-03T11:06:45Z The amino‐acid sequence and the oxygen‐binding properties of the two haemoglobins of the Antarctic seabird south polar skua have been investigated. The two haemoglobins showed peculiar functional features, which were probably acquired to meet special needs in relation to the extreme environmental conditions. Both haemoglobins showed a weak alkaline Bohr effect which, during prolonged flight, may protect against sudden and uncontrolled stripping of oxygen in response to acidosis. We suggest that a weak Bohr effect in birds may reflect adaptation to extreme life conditions. The values of heat of oxygenation suggest different functional roles of the two haemoglobins. The experimental evidence suggests that both haemoglobins may bind phosphate at two distinct binding sites. In fact, analysis of the molecular models revealed that an additional phosphate binding site, formed by residues NA1α, G6α and HC3α, is located between the two α chains. This additional site may act as an entry/leaving site, thus increasing the probability of capturing phosphate and transferring it to the main binding site located between the two β chains by means of a site–site migratory mechanism, thereby favouring the release of oxygen. It is suggested that most haemoglobins possess an additional phosphate binding site, having such a role in oxygen transport. Article in Journal/Newspaper Antarc* Antarctic Catharacta maccormicki Wiley Online Library Antarctic The Antarctic European Journal of Biochemistry 267 19 6089 6098 |
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Open Polar |
collection |
Wiley Online Library |
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crwiley |
language |
English |
description |
The amino‐acid sequence and the oxygen‐binding properties of the two haemoglobins of the Antarctic seabird south polar skua have been investigated. The two haemoglobins showed peculiar functional features, which were probably acquired to meet special needs in relation to the extreme environmental conditions. Both haemoglobins showed a weak alkaline Bohr effect which, during prolonged flight, may protect against sudden and uncontrolled stripping of oxygen in response to acidosis. We suggest that a weak Bohr effect in birds may reflect adaptation to extreme life conditions. The values of heat of oxygenation suggest different functional roles of the two haemoglobins. The experimental evidence suggests that both haemoglobins may bind phosphate at two distinct binding sites. In fact, analysis of the molecular models revealed that an additional phosphate binding site, formed by residues NA1α, G6α and HC3α, is located between the two α chains. This additional site may act as an entry/leaving site, thus increasing the probability of capturing phosphate and transferring it to the main binding site located between the two β chains by means of a site–site migratory mechanism, thereby favouring the release of oxygen. It is suggested that most haemoglobins possess an additional phosphate binding site, having such a role in oxygen transport. |
format |
Article in Journal/Newspaper |
author |
Tamburrini, Maurizio Riccio, Antonio Romano, Maurizio Giardina, Bruno di Prisco, Guido |
spellingShingle |
Tamburrini, Maurizio Riccio, Antonio Romano, Maurizio Giardina, Bruno di Prisco, Guido Structural and functional analysis of the two haemoglobins of the Antarctic seabird Catharacta maccormicki |
author_facet |
Tamburrini, Maurizio Riccio, Antonio Romano, Maurizio Giardina, Bruno di Prisco, Guido |
author_sort |
Tamburrini, Maurizio |
title |
Structural and functional analysis of the two haemoglobins of the Antarctic seabird Catharacta maccormicki |
title_short |
Structural and functional analysis of the two haemoglobins of the Antarctic seabird Catharacta maccormicki |
title_full |
Structural and functional analysis of the two haemoglobins of the Antarctic seabird Catharacta maccormicki |
title_fullStr |
Structural and functional analysis of the two haemoglobins of the Antarctic seabird Catharacta maccormicki |
title_full_unstemmed |
Structural and functional analysis of the two haemoglobins of the Antarctic seabird Catharacta maccormicki |
title_sort |
structural and functional analysis of the two haemoglobins of the antarctic seabird catharacta maccormicki |
publisher |
Wiley |
publishDate |
2000 |
url |
http://dx.doi.org/10.1046/j.1432-1327.2000.01699.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1432-1327.2000.01699.x https://febs.onlinelibrary.wiley.com/doi/pdf/10.1046/j.1432-1327.2000.01699.x |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Catharacta maccormicki |
genre_facet |
Antarc* Antarctic Catharacta maccormicki |
op_source |
European Journal of Biochemistry volume 267, issue 19, page 6089-6098 ISSN 0014-2956 1432-1033 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1046/j.1432-1327.2000.01699.x |
container_title |
European Journal of Biochemistry |
container_volume |
267 |
container_issue |
19 |
container_start_page |
6089 |
op_container_end_page |
6098 |
_version_ |
1800741867062558720 |