Correlation between functional and structural changes of reduced and oxidized trout hemoglobins I and IV at different pHs

Gabbianelli, Rosita; Zolese, Giovanna; Bertoli, Enrico; Falcioni, Giancarlo

doi:10.1111/j.1432-1033.2004.04109.x

Cited by 19 publications

(20 citation statements)

References 37 publications

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“…The crystal structure of the aFe(II)(CO)bFe(III)(pentacoordinated) state, which may be considered a half liganded form, also provided a detailed framework of the heme-heme communication path within the tetramer. 14 Interestingly, the peculiar intermediate (pentacoordinated) and final (bis-histidine) states of the oxidation of AF-Hb were not observed in temperate fish Hbs, such as trout, 23 and sea-bass. 17 The major component of the Antarctic fish Trematomus bernacchii (HbTb) is a protein that is closely related to Hb1Tn.…”

Section: Introductionmentioning

confidence: 85%

Combined crystallographic and spectroscopic analysis of Trematomus bernacchii hemoglobin highlights analogies and differences in the peculiar oxidation pathway of Antarctic fish hemoglobins

et al. 2009

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Recent studies have demonstrated that hemoglobins isolated from Antarctic fish undergo peculiar oxidation processes. Here we show, by combining crystallographic and spectroscopic data, that the oxidation pathway of Trematomus bernacchii hemoglobin (HbTb) is distinct from that observed for the major component of Trematomus newnesi (Hb1Tn), despite the high sequence identity of the two proteins and structural similarity of their ferrous and fully oxidized states. Resonance Raman analysis of HbTb autoxidation upon air-exposure reveals the absence of the oxidized pentacoordinated state that was observed for Hb1Tn. The HbTb oxidation pathway is characterized by two ferric species: an aquo hexacoordinated high spin state and a bis-histidyl hexacoordinated low spin form, which appear in the early stages of the oxidation process. The high resolution structure of an intermediate along the oxidation pathway has been determined at 1.4 A resolution. The analysis of the electron density of the heme pocket shows, for both the alpha and the beta iron, the coexistence of multiple binding states. In this partially oxidized form, HbTb exhibits significant deviations from the canonical R state both at the local and global level. The analysis of these modifications highlights the structural correlation between key functional regions of the protein.

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Section: Introductionmentioning

confidence: 85%

Combined crystallographic and spectroscopic analysis of Trematomus bernacchii hemoglobin highlights analogies and differences in the peculiar oxidation pathway of Antarctic fish hemoglobins

et al. 2009

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“…The auto-oxidation rate in temperate fish Hbs is higher than in mammals [71], and in Antarctic fish Hbs it is even higher than in temperate fish; actually, after a few hours of air exposure Antarctic fish Hb undergoes partial autooxidation [65]. This implies that under physiological condition a relatively high fraction of Hb is in a potentially functional ferric form.…”

Section: Oxidation Of Hbs and Its Relevance To Polar Fish Physiologymentioning

confidence: 96%

The Hemoglobins of Fishes Living at Polar Latitudes - Current Knowledge on Structural Adaptations in a Changing Environment

Verde¹,

Vergara²,

Mazzarella³

et al. 2008

CPPS

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Fishes thriving in polar habitats offer many opportunities for comparative approaches to understanding protein adaptations to temperature. Notothenioidei, the dominant suborder in the Antarctic Ocean, have evolved reduction of hemoglobin concentration and multiplicity, perhaps as a consequence of temperature stability and other environmental parameters. In the icefish family, the blood pigment is absent. In contrast, similar to other acanthomorph teleosts, Arctic fish, thriving in a more complex oceanographic system, have maintained higher hemoglobin multiplicity and a highly diversified globin system in response to environmental variability and/or variations in metabolic demands. This review summarises the current knowledge on the structure, function and phylogeny of hemoglobins of fish living in polar habitats. On the basis of crystallographic analysis, a novel guideline to the interpretation of the Root effect in terms of a three-state model is suggested, implying the accessibility of an R/T intermediate quaternary structure, frequently observed in Antarctic fish hemoglobins. The occurrence of bis-histidyl and penta-coordinate states in ferric forms of polar fish hemoglobins suggests additional redox properties.

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“…At low pH it displays a Root effect causing oxygen release into the swim bladder and the retina. At pH 7.8, hemoglobin IV is totally oxygenated, while at pH 6.0, it is fully deoxygenated (49,50).…”

Section: 3mentioning

confidence: 99%

“…Fish hemoglobins www.bjournal.com.br does not present a Bohr effect and is not sensitive to organic phosphates, whereas hemoglobin IV (60% of the total) has a Bohr effect and is sensitive to organic phosphates, also exhibiting a loss of cooperativity at low pH, showing the presence of a Root effect (49). Hemoglobin IV is the major O 2 carrier, consisting of three types of beta chains in equal quantities and three types of alpha chains.…”

Section: 3mentioning

confidence: 99%

Fish hemoglobins

Souza

Bonilla-Rodriguez

2007

Braz J Med Biol Res

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Vertebrate hemoglobin, contained in erythrocytes, is a globular protein with a quaternary structure composed of 4 globin chains (2 alpha and 2 beta) and a prosthetic group named heme bound to each one. Having myoglobin as an ancestor, hemoglobin acquired the capacity to respond to chemical stimuli that modulate its function according to tissue requirements for oxygen. Fish are generally submitted to spatial and temporal O 2 variations and have developed anatomical, physiological and biochemical strategies to adapt to the changing environmental gas availability. Structurally, most fish hemoglobins are tetrameric; however, those from some species such as lamprey and hagfish dissociate, being monomeric when oxygenated and oligomeric when deoxygenated. Fish blood frequently possesses several hemoglobins; the primary origin of this finding lies in the polymorphism that occurs in the globin loci, an aspect that may occasionally confer advantages to its carriers or even be a harmless evolutionary remnant. On the other hand, the functional properties exhibit different behaviors, ranging from a total absence of responses to allosteric regulation to drastic ones, such as the Root effect.

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Correlation between functional and structural changes of reduced and oxidized trout hemoglobins I and IV at different pHs

Cited by 19 publications

References 37 publications

Combined crystallographic and spectroscopic analysis of Trematomus bernacchii hemoglobin highlights analogies and differences in the peculiar oxidation pathway of Antarctic fish hemoglobins

Combined crystallographic and spectroscopic analysis of Trematomus bernacchii hemoglobin highlights analogies and differences in the peculiar oxidation pathway of Antarctic fish hemoglobins

The Hemoglobins of Fishes Living at Polar Latitudes - Current Knowledge on Structural Adaptations in a Changing Environment

Fish hemoglobins

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