Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii
The Root effect describes the drastic drop of oxygen affinity and loss of cooperativity at acidic pH expressed in the hemoglobins (Hb) of certain fish. The comparison between the deoxy structures of the Root effect Hb from the Antarctic fish Trematomus bernacchii (HbTb) at different pHs (pH = 6.2 an...
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2011
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15216543_v63_n3_p175_Boechi http://hdl.handle.net/20.500.12110/paper_15216543_v63_n3_p175_Boechi |
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paper:paper_15216543_v63_n3_p175_Boechi2023-06-08T16:19:17Z Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii hemoglobin implicit ligand sampling molecular dynamics simulations oxygen binding pH Trematomus bernacchii hemoglobin histidine Antarctica computer simulation conference paper controlled study fish human nonhuman oxygen affinity protein conformation protein function protein structure proton transport trematomus bernacchii Animals Antarctic Regions Heme Hemoglobins Histidine Models, Molecular Oxygen Protons Trematomus bernacchii The Root effect describes the drastic drop of oxygen affinity and loss of cooperativity at acidic pH expressed in the hemoglobins (Hb) of certain fish. The comparison between the deoxy structures of the Root effect Hb from the Antarctic fish Trematomus bernacchii (HbTb) at different pHs (pH = 6.2 and pH = 8.4) shows that the most significant differences are localized at the CDα region, where a salt bridge between Asp48 and His55 breaks during the low-to-high pH transition. In order to shed light on the relationship between pH, CDα loop structure and dynamics, and oxygen access to the active site in the alpha chain of HbTb, different computer simulation techniques were performed. Our results highlight the importance of the protonation of His55 in regulating oxygen access, underscoring its pivotal role in the structural and functional properties of HbTb. These data provide further support to the hypothesis that this residue might contribute to the release of Root protons in HbTb and underline the fact that an efficient transport of molecular oxygen in Hbs relies on a subtle balance of tertiary structure and protein conformational flexibility. © 2011 IUBMB. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15216543_v63_n3_p175_Boechi http://hdl.handle.net/20.500.12110/paper_15216543_v63_n3_p175_Boechi |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
hemoglobin implicit ligand sampling molecular dynamics simulations oxygen binding pH Trematomus bernacchii hemoglobin histidine Antarctica computer simulation conference paper controlled study fish human nonhuman oxygen affinity protein conformation protein function protein structure proton transport trematomus bernacchii Animals Antarctic Regions Heme Hemoglobins Histidine Models, Molecular Oxygen Protons Trematomus bernacchii |
| spellingShingle |
hemoglobin implicit ligand sampling molecular dynamics simulations oxygen binding pH Trematomus bernacchii hemoglobin histidine Antarctica computer simulation conference paper controlled study fish human nonhuman oxygen affinity protein conformation protein function protein structure proton transport trematomus bernacchii Animals Antarctic Regions Heme Hemoglobins Histidine Models, Molecular Oxygen Protons Trematomus bernacchii Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii |
| topic_facet |
hemoglobin implicit ligand sampling molecular dynamics simulations oxygen binding pH Trematomus bernacchii hemoglobin histidine Antarctica computer simulation conference paper controlled study fish human nonhuman oxygen affinity protein conformation protein function protein structure proton transport trematomus bernacchii Animals Antarctic Regions Heme Hemoglobins Histidine Models, Molecular Oxygen Protons Trematomus bernacchii |
| description |
The Root effect describes the drastic drop of oxygen affinity and loss of cooperativity at acidic pH expressed in the hemoglobins (Hb) of certain fish. The comparison between the deoxy structures of the Root effect Hb from the Antarctic fish Trematomus bernacchii (HbTb) at different pHs (pH = 6.2 and pH = 8.4) shows that the most significant differences are localized at the CDα region, where a salt bridge between Asp48 and His55 breaks during the low-to-high pH transition. In order to shed light on the relationship between pH, CDα loop structure and dynamics, and oxygen access to the active site in the alpha chain of HbTb, different computer simulation techniques were performed. Our results highlight the importance of the protonation of His55 in regulating oxygen access, underscoring its pivotal role in the structural and functional properties of HbTb. These data provide further support to the hypothesis that this residue might contribute to the release of Root protons in HbTb and underline the fact that an efficient transport of molecular oxygen in Hbs relies on a subtle balance of tertiary structure and protein conformational flexibility. © 2011 IUBMB. |
| title |
Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii |
| title_short |
Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii |
| title_full |
Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii |
| title_fullStr |
Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii |
| title_full_unstemmed |
Protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the Antarctic fish Trematomus bernacchii |
| title_sort |
protonation of histidine 55 affects the oxygen access to heme in the alpha chain of the hemoglobin from the antarctic fish trematomus bernacchii |
| publishDate |
2011 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15216543_v63_n3_p175_Boechi http://hdl.handle.net/20.500.12110/paper_15216543_v63_n3_p175_Boechi |
| _version_ |
1768546739415941120 |