Synergistic modulation by chloride and organic phosphates of hemoglobin from bear (Ursus arctos)
The oxygen binding properties of hemoglobin (Hb) from brown bear (Ursus arctos) have been studied focussing on the effect of heterotropic ligands, and the behaviour has been compared with that of human HbA, taken as a prototype of mammalian Hbs. It has been observed that in bear Hb chloride ions and...
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ftunivromatorver:oai:art.torvergata.it:2108/54672 2023-08-20T04:10:16+02:00 Synergistic modulation by chloride and organic phosphates of hemoglobin from bear (Ursus arctos) COLETTA, MASSIMILIANO CONDO', SAVERIO GIOVANNI Scatena, R Clementi, M Baroni, S Sletten, S Brix, O Giardina, B. Coletta, M Condo', Sg Scatena, R Clementi, M Baroni, S Sletten, S Brix, O Giardina, B 1994-03-11 http://hdl.handle.net/2108/54672 eng eng volume:236 issue:5 firstpage:1401 lastpage:1406 journal:JOURNAL OF MOLECULAR BIOLOGY http://hdl.handle.net/2108/54672 Animal Ursidae Oxyhemoglobin Hemoglobin Hydrogen-Ion Concentration Diphosphoglyceric Acid Chlorides Settore BIO/10 - BIOCHIMICA info:eu-repo/semantics/article 1994 ftunivromatorver 2023-08-01T23:07:37Z The oxygen binding properties of hemoglobin (Hb) from brown bear (Ursus arctos) have been studied focussing on the effect of heterotropic ligands, and the behaviour has been compared with that of human HbA, taken as a prototype of mammalian Hbs. It has been observed that in bear Hb chloride ions and 2,3-diphosphoglyceric acid (Gri(2,3)P2) can modulate the oxygen affinity in a synergistic way such that their individual effect is enhanced whenever they are both present in saturating amounts. The thermodynamic analysis of such a feature indicates that in bear Hb there are two classes of chloride binding sites, one acting synergistically with Gri(2,3)P2 and another one, which likely overlaps with the organic phosphate interaction cleft, and is therefore fully operative only in the absence of Gri(2,3)P2. The behaviour of the last site is similar to that observed in human HbA, where the effect of Cl- and Gri(2,3)P2 is mutually exclusive. The interaction energy between chloride and Gri(2,3)P2 synergistic binding sites appears to be O2-linked so that the interplay may have a relevant physiological role in modulating the oxygen transport in brown bear. This behaviour is associated with a marked pH-dependence of the oxygenation enthalpy in bear Hb, such that under acidotic and hypercloruremic conditions, oxygen supply to peripheral tissues could be maintained essentially unaltered even under low temperature conditions. Article in Journal/Newspaper Ursus arctos Universitá degli Studi di Roma "Tor Vergata": ART - Archivio Istituzionale della Ricerca |
institution |
Open Polar |
collection |
Universitá degli Studi di Roma "Tor Vergata": ART - Archivio Istituzionale della Ricerca |
op_collection_id |
ftunivromatorver |
language |
English |
topic |
Animal Ursidae Oxyhemoglobin Hemoglobin Hydrogen-Ion Concentration Diphosphoglyceric Acid Chlorides Settore BIO/10 - BIOCHIMICA |
spellingShingle |
Animal Ursidae Oxyhemoglobin Hemoglobin Hydrogen-Ion Concentration Diphosphoglyceric Acid Chlorides Settore BIO/10 - BIOCHIMICA COLETTA, MASSIMILIANO CONDO', SAVERIO GIOVANNI Scatena, R Clementi, M Baroni, S Sletten, S Brix, O Giardina, B. Synergistic modulation by chloride and organic phosphates of hemoglobin from bear (Ursus arctos) |
topic_facet |
Animal Ursidae Oxyhemoglobin Hemoglobin Hydrogen-Ion Concentration Diphosphoglyceric Acid Chlorides Settore BIO/10 - BIOCHIMICA |
description |
The oxygen binding properties of hemoglobin (Hb) from brown bear (Ursus arctos) have been studied focussing on the effect of heterotropic ligands, and the behaviour has been compared with that of human HbA, taken as a prototype of mammalian Hbs. It has been observed that in bear Hb chloride ions and 2,3-diphosphoglyceric acid (Gri(2,3)P2) can modulate the oxygen affinity in a synergistic way such that their individual effect is enhanced whenever they are both present in saturating amounts. The thermodynamic analysis of such a feature indicates that in bear Hb there are two classes of chloride binding sites, one acting synergistically with Gri(2,3)P2 and another one, which likely overlaps with the organic phosphate interaction cleft, and is therefore fully operative only in the absence of Gri(2,3)P2. The behaviour of the last site is similar to that observed in human HbA, where the effect of Cl- and Gri(2,3)P2 is mutually exclusive. The interaction energy between chloride and Gri(2,3)P2 synergistic binding sites appears to be O2-linked so that the interplay may have a relevant physiological role in modulating the oxygen transport in brown bear. This behaviour is associated with a marked pH-dependence of the oxygenation enthalpy in bear Hb, such that under acidotic and hypercloruremic conditions, oxygen supply to peripheral tissues could be maintained essentially unaltered even under low temperature conditions. |
author2 |
Coletta, M Condo', Sg Scatena, R Clementi, M Baroni, S Sletten, S Brix, O Giardina, B |
format |
Article in Journal/Newspaper |
author |
COLETTA, MASSIMILIANO CONDO', SAVERIO GIOVANNI Scatena, R Clementi, M Baroni, S Sletten, S Brix, O Giardina, B. |
author_facet |
COLETTA, MASSIMILIANO CONDO', SAVERIO GIOVANNI Scatena, R Clementi, M Baroni, S Sletten, S Brix, O Giardina, B. |
author_sort |
COLETTA, MASSIMILIANO |
title |
Synergistic modulation by chloride and organic phosphates of hemoglobin from bear (Ursus arctos) |
title_short |
Synergistic modulation by chloride and organic phosphates of hemoglobin from bear (Ursus arctos) |
title_full |
Synergistic modulation by chloride and organic phosphates of hemoglobin from bear (Ursus arctos) |
title_fullStr |
Synergistic modulation by chloride and organic phosphates of hemoglobin from bear (Ursus arctos) |
title_full_unstemmed |
Synergistic modulation by chloride and organic phosphates of hemoglobin from bear (Ursus arctos) |
title_sort |
synergistic modulation by chloride and organic phosphates of hemoglobin from bear (ursus arctos) |
publishDate |
1994 |
url |
http://hdl.handle.net/2108/54672 |
genre |
Ursus arctos |
genre_facet |
Ursus arctos |
op_relation |
volume:236 issue:5 firstpage:1401 lastpage:1406 journal:JOURNAL OF MOLECULAR BIOLOGY http://hdl.handle.net/2108/54672 |
_version_ |
1774724341936685056 |