High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect.
The Root effect is a widespread property in fish hemoglobins (Hbs) that produces a drastic reduction of cooperativity and oxygenbinding ability at acidic pH. Here, we report the high-resolution structure of the deoxy form of Hb isolated from the Antarctic fish Trematomus bernacchii (HbTb) crystalliz...
Published in: | Proteins: Structure, Function, and Bioinformatics |
---|---|
Main Authors: | , , , , , , , |
Other Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2006
|
Subjects: | |
Online Access: | http://hdl.handle.net/11588/201961 https://doi.org/10.1002/prot.21114 |
id |
ftunivnapoliiris:oai:www.iris.unina.it:11588/201961 |
---|---|
record_format |
openpolar |
spelling |
ftunivnapoliiris:oai:www.iris.unina.it:11588/201961 2024-09-09T19:09:06+00:00 High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect. MAZZARELLA, LELIO VERGARA, ALESSANDRO MERLINO, ANTONELLO L. VITAGLIANO G. BONOMI S. SCALA C. VERDE G. DI PRISCO Mazzarella, Lelio Vergara, Alessandro L., Vitagliano Merlino, Antonello G., Bonomi S., Scala C., Verde G., DI PRISCO 2006 STAMPA http://hdl.handle.net/11588/201961 https://doi.org/10.1002/prot.21114 eng eng info:eu-repo/semantics/altIdentifier/pmid/16909420 info:eu-repo/semantics/altIdentifier/wos/WOS:000240748700020 volume:65 issue:2 firstpage:490 lastpage:498 numberofpages:9 journal:PROTEINS http://hdl.handle.net/11588/201961 doi:10.1002/prot.21114 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-33748996221 info:eu-repo/semantics/closedAccess info:eu-repo/semantics/article 2006 ftunivnapoliiris https://doi.org/10.1002/prot.21114 2024-06-17T15:19:24Z The Root effect is a widespread property in fish hemoglobins (Hbs) that produces a drastic reduction of cooperativity and oxygenbinding ability at acidic pH. Here, we report the high-resolution structure of the deoxy form of Hb isolated from the Antarctic fish Trematomus bernacchii (HbTb) crystallized at pH 6.2 and 8.4. The structure at acidic pH has been previously determined at a moderate resolution (Ito et al., J Mol Biol 1995;250:648–658). Our results provide a clear picture of the events occurring upon the pH increase from 6.2 to 8.4, observed within a practically unchanged crystal environment. In particular, at pH 8.4, the interaspartic hydrogen bond at the a1b2 interface is partially broken, suggesting a pKa close to 8.4 for Asp95a. In addition, a detailed survey of the histidine modifications, caused by the change in pH, also indicates that at least three hot regions of the molecule are modified (Eb helix, Cb-tail, CDa corner) and can be considered to be involved at various levels in the release of the Root protons. Most importantly, at the CDa corner, the break of the salt bridge Asp48a–His55a allows us to describe a detailed mechanism that transmits the modification from the CDa corner far to the a heme. More generally, the results shed light on the role played by the histidine residues in modulating the strength of the Root effect and also support the emerging idea that the structural determinants, at least for a part of the Root effect, are specific of each Hb endowed with this property Article in Journal/Newspaper Antarc* Antarctic IRIS Università degli Studi di Napoli Federico II Antarctic The Antarctic Proteins: Structure, Function, and Bioinformatics 65 2 490 498 |
institution |
Open Polar |
collection |
IRIS Università degli Studi di Napoli Federico II |
op_collection_id |
ftunivnapoliiris |
language |
English |
description |
The Root effect is a widespread property in fish hemoglobins (Hbs) that produces a drastic reduction of cooperativity and oxygenbinding ability at acidic pH. Here, we report the high-resolution structure of the deoxy form of Hb isolated from the Antarctic fish Trematomus bernacchii (HbTb) crystallized at pH 6.2 and 8.4. The structure at acidic pH has been previously determined at a moderate resolution (Ito et al., J Mol Biol 1995;250:648–658). Our results provide a clear picture of the events occurring upon the pH increase from 6.2 to 8.4, observed within a practically unchanged crystal environment. In particular, at pH 8.4, the interaspartic hydrogen bond at the a1b2 interface is partially broken, suggesting a pKa close to 8.4 for Asp95a. In addition, a detailed survey of the histidine modifications, caused by the change in pH, also indicates that at least three hot regions of the molecule are modified (Eb helix, Cb-tail, CDa corner) and can be considered to be involved at various levels in the release of the Root protons. Most importantly, at the CDa corner, the break of the salt bridge Asp48a–His55a allows us to describe a detailed mechanism that transmits the modification from the CDa corner far to the a heme. More generally, the results shed light on the role played by the histidine residues in modulating the strength of the Root effect and also support the emerging idea that the structural determinants, at least for a part of the Root effect, are specific of each Hb endowed with this property |
author2 |
Mazzarella, Lelio Vergara, Alessandro L., Vitagliano Merlino, Antonello G., Bonomi S., Scala C., Verde G., DI PRISCO |
format |
Article in Journal/Newspaper |
author |
MAZZARELLA, LELIO VERGARA, ALESSANDRO MERLINO, ANTONELLO L. VITAGLIANO G. BONOMI S. SCALA C. VERDE G. DI PRISCO |
spellingShingle |
MAZZARELLA, LELIO VERGARA, ALESSANDRO MERLINO, ANTONELLO L. VITAGLIANO G. BONOMI S. SCALA C. VERDE G. DI PRISCO High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect. |
author_facet |
MAZZARELLA, LELIO VERGARA, ALESSANDRO MERLINO, ANTONELLO L. VITAGLIANO G. BONOMI S. SCALA C. VERDE G. DI PRISCO |
author_sort |
MAZZARELLA, LELIO |
title |
High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect. |
title_short |
High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect. |
title_full |
High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect. |
title_fullStr |
High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect. |
title_full_unstemmed |
High resolution crystal structure of deoxy hemoglobin from Trematomus bernacchii at different pH values: the role of histidine residues in modulating the strength of the root effect. |
title_sort |
high resolution crystal structure of deoxy hemoglobin from trematomus bernacchii at different ph values: the role of histidine residues in modulating the strength of the root effect. |
publishDate |
2006 |
url |
http://hdl.handle.net/11588/201961 https://doi.org/10.1002/prot.21114 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
info:eu-repo/semantics/altIdentifier/pmid/16909420 info:eu-repo/semantics/altIdentifier/wos/WOS:000240748700020 volume:65 issue:2 firstpage:490 lastpage:498 numberofpages:9 journal:PROTEINS http://hdl.handle.net/11588/201961 doi:10.1002/prot.21114 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-33748996221 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1002/prot.21114 |
container_title |
Proteins: Structure, Function, and Bioinformatics |
container_volume |
65 |
container_issue |
2 |
container_start_page |
490 |
op_container_end_page |
498 |
_version_ |
1809823385422659584 |