scholarly journals Temperature modulation of oxygen transport in a diving mammal (Balaenoptera acutorostrata)

1990 ◽  
Vol 271 (2) ◽  
pp. 509-513 ◽  
Author(s):  
O Brix ◽  
S G Condò ◽  
A Bardgard ◽  
B Tavazzi ◽  
B Giardina
Keyword(s):  
Carbon Dioxide ◽  
Functional Properties ◽  
Oxygen Transport ◽  
Temperature Modulation ◽  
Oxygen Binding ◽  
Balaenoptera Acutorostrata ◽  
Organic Phosphates

The functional properties of haemoglobin from the Lesser Rorqual whale (Balaenoptera acutorostrata) have been characterized as a function of the heterotropic effector concentrations and temperature. The results obtained suggest the existence of sophisticated modulation mechanisms based on the interplay of organic phosphates, carbon dioxide, lactate and temperature. These, together with the very small apparent heat of oxygenation (delta H) of oxygen binding, have been physiologically interpreted on the basis of the specific metabolic needs of this diving mammal.

Quaternary structure of Limulus polyphemus hemocyanin

1978 ◽  
Vol 36 (2) ◽  
pp. 176-177
Author(s):  
T. Wichertjes ◽  
E.J. Kwak ◽  
E.F.J. Van Bruggen
Keyword(s):  
Electron Microscopy ◽  
Functional Properties ◽  
Horseshoe Crab ◽  
Temperature Jump ◽  
Quaternary Structure ◽  
Crystallographic Analysis ◽  
Limulus Polyphemus ◽  
Oxygen Binding ◽  
X Ray ◽  
Intact Molecule

Hemocyanin of the horseshoe crab (Limulus polyphemus) has been studied in nany ways. Recently the structure, dissociation and reassembly was studied using electron microscopy of negatively stained specimens as the method of investigation. Crystallization of the protein proved to be possible and X-ray crystallographic analysis was started. Also fluorescence properties of the hemocyanin after dialysis against Tris-glycine buffer + 0.01 M EDTA pH 8.9 (so called “stripped” hemocyanin) and its fractions II and V were studied, as well as functional properties of the fractions by NMR. Finally the temperature-jump method was used for assaying the oxygen binding of the dissociating molecule and of preparations of isolated subunits. Nevertheless very little is known about the structure of the intact molecule. Schutter et al. suggested that the molecule possibly consists of two halves, combined in a staggered way, the halves themselves consisting of four subunits arranged in a square.

scholarly journals Adult and fetal haemoglobin J-Sardegna [α50(CE8)His→Asp]: functional and molecular modelling studies

2000 ◽  
Vol 346 (1) ◽  
pp. 193-199 ◽  
Author(s):  
Marcella CORDA ◽  
Maria C. DE ROSA ◽  
Maria G. PELLEGRINI ◽  
Maria T. SANNA ◽  
Alessandra OLIANAS ◽  
...  
Keyword(s):  
Functional Properties ◽  
Computational Modelling ◽  
Oxygen Affinity ◽  
Oxygen Binding ◽  
Structural Level ◽  
Fetal Haemoglobin ◽  
Significant Difference ◽  
Molecular Modelling Studies ◽  
Modelling Studies ◽  
2,3 Dpg

Haemoglobin (Hb) J-Sardegna [α50(CE8)His → Asp] is a haemoglobin variant characteristic of subjects from the island of Sardinia. Here we report a study of the functional properties of both fetal and adult Hb J-Sardegna. The results indicate that adult Hb J-Sardegna displays an oxygen affinity that is higher than that of adult Hb only in the presence of 2,3-diphosphoglycerate (2,3-DPG). On the contrary, at 20 °C, the oxygen affinity of fetal Hb J-Sardegna is identical to that of normal fetal haemoglobin, both in the presence and in the absence of 2,3-DPG. A significant difference between these two systems (i.e. a higher oxygen affinity of fetal Hb J-Sardegna) shows up very clearly only when temperature is increased to 37 °C. Hence in fetal Hb, the main effect of the amino acid substitution is a decrease in the overall enthalpy change of oxygenation. The results outline the role of the α1-β1 interface in assessing the thermodynamics of oxygen binding. The functional properties of both adult and fetal Hb J-Sardegna have been interpreted at the structural level in light of the results obtained by a computational modelling approach performed in comparison with HbA and Hb Aichi, a variant characterized by a different mutation [α50(CE8)His → Arg] at the same position.

Oxygen-tolerant electroproduction of C2 products from simulated flue gas

2020 ◽  
Vol 13 (2) ◽  
pp. 554-561 ◽  
Author(s):  
Yi Xu ◽  
Jonathan P. Edwards ◽  
Junjie Zhong ◽  
Colin P. O’Brien ◽  
Christine M. Gabardo ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Transport ◽  
Flue Gas ◽  
Catalyst Support

A hydrated ionomer catalyst support layer, capable of slowing oxygen transport, enables the generation of multi-carbon products from pressurized, oxygen-containing, dilute carbon dioxide feedstocks.

Oxygen Transport Membrane for Thermochemical Conversion of Water and Carbon Dioxide into Synthesis Gas

2017 ◽  
Vol 5 (10) ◽  
pp. 8657-8662 ◽  
Author(s):  
Wenyuan Liang ◽  
Zhengwen Cao ◽  
Guanghu He ◽  
Jürgen Caro ◽  
Heqing Jiang
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Transport ◽  
Synthesis Gas ◽  
Thermochemical Conversion ◽  
Oxygen Transport Membrane

Oxygen transport by rabbit embryonic blood: high cooperativity of hemoglobin-oxygen binding

1995 ◽  
Vol 99 (1) ◽  
pp. 157-164 ◽  
Author(s):  
Robert A.B. Holland ◽  
Susan J. Calvert
Keyword(s):  
Oxygen Transport ◽  
Oxygen Binding

scholarly journals Molecular evolution and expression of oxygen transport genes in livebearing fishes (Poeciliidae) from hydrogen sulfide rich springs

Genome ◽  
2018 ◽  
Vol 61 (4) ◽  
pp. 273-286 ◽  
Author(s):  
Nicholas Barts ◽  
Ryan Greenway ◽  
Courtney N. Passow ◽  
Lenin Arias-Rodriguez ◽  
Joanna L. Kelley ◽  
...  
Keyword(s):  
Gene Expression ◽  
Hydrogen Sulfide ◽  
Molecular Evolution ◽  
Oxygen Transport ◽  
Transport Proteins ◽  
Aquatic Environments ◽  
Oxygen Binding ◽  
The Family ◽  
Signatures Of Selection ◽  
Evolution Of Oxygen

Hydrogen sulfide (H2S) is a natural toxicant in some aquatic environments that has diverse molecular targets. It binds to oxygen transport proteins, rendering them non-functional by reducing oxygen-binding affinity. Hence, organisms permanently inhabiting H2S-rich environments are predicted to exhibit adaptive modifications to compensate for the reduced capacity to transport oxygen. We investigated 10 lineages of fish of the family Poeciliidae that have colonized freshwater springs rich in H2S—along with related lineages from non-sulfidic environments—to test hypotheses about the expression and evolution of oxygen transport genes in a phylogenetic context. We predicted shifts in the expression of and signatures of positive selection on oxygen transport genes upon colonization of H2S-rich habitats. Our analyses indicated significant shifts in gene expression for multiple hemoglobin genes in lineages that have colonized H2S-rich environments, and three hemoglobin genes exhibited relaxed selection in sulfidic compared to non-sulfidic lineages. However, neither changes in gene expression nor signatures of selection were consistent among all lineages in H2S-rich environments. Oxygen transport genes may consequently be predictable targets of selection during adaptation to sulfidic environments, but changes in gene expression and molecular evolution of oxygen transport genes in H2S-rich environments are not necessarily repeatable across replicated lineages.

scholarly journals Gene Duplication and Evolutionary Innovations in Hemoglobin-Oxygen Transport

Physiology ◽  
2016 ◽  
Vol 31 (3) ◽  
pp. 223-232 ◽  
Author(s):  
Jay F. Storz
Keyword(s):  
Gene Duplication ◽  
Functional Properties ◽  
Oxygen Transport ◽  
Developmental Stages ◽  
Functional Differentiation ◽  
Vertebrate Evolution ◽  
Developmental Timing

During vertebrate evolution, duplicated hemoglobin (Hb) genes diverged with respect to functional properties as well as the developmental timing of expression. For example, the subfamilies of genes that encode the different subunit chains of Hb are ontogenetically regulated such that functionally distinct Hb isoforms are expressed during different developmental stages. In some vertebrate taxa, functional differentiation between co-expressed Hb isoforms may also contribute to physiologically important divisions of labor.

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