scholarly journals Kinesthetic and visual scaffolding for understanding oxygen delivery and reading hemoglobin oxygen curves

2021 ◽  
Vol 45 (1) ◽  
pp. 121-128
Author(s):  
Mark A. Milanick
Keyword(s):  
Oxygen Delivery ◽  
Oxygen Binding ◽  
Binding Curve

I describe a kinesthetic activity about oxygen handling by hemoglobin with two specific goals: 1) to help students gain a better understanding of how hemoglobin properties affect oxygen delivery and 2) to improve the ability of the students to actually read the hemoglobin oxygen-binding curve. The activity makes understanding oxygen delivery more intuitive, provides a kinesthetic analog to delivery of oxygen, and provides data to plot for the hemoglobin-oxygen curve.

scholarly journals Analysis of oxygen binding by hemoglobin on the basis of mean intrinsic thermodynamic quantities.

2006 ◽  
Vol 53 (3) ◽  
pp. 563-568 ◽  
Author(s):  
Abdol-Khalegh Bordbar ◽  
Sayed Habib-Allah Mousavi ◽  
Hamid Dazhampanah
Keyword(s):  
Binding Affinity ◽  
Compensation Effect ◽  
Cooperative Interaction ◽  
Thermodynamic Quantities ◽  
Oxygen Binding ◽  
Protein Species ◽  
Binding Data ◽  
Hoff Equation ◽  
Binding Curve ◽  
Partial Oxygen

The binding data for oxygenation of human hemoglobin, Hb, at various temperatures and in the absence and presence of 2,3-diphosphoglycerate, DPG, and inositol hexakis phosphate, IHP, were analyzed for extraction of mean intrinsic Gibbs free energy, DeltaGo, enthalpy, DeltaHo, and entropy, DeltaSo, of binding at various partial oxygen pressures. This method of analysis considers all the protein species present such as dimer and tetramer forms which were not considered by Imai et al. (Imai K et al., 1970, Biochim Biophys Acta 200: 189-196), in their analysis which was based on Adair equation. In this regard, the values of Hill equation parameters were estimated with high precision at all points of the binding curve and used for calculation of DeltaGo, DeltaHo and DeltaSo were also calculated by analysis of DeltaGo values at various temperatures using van't Hoff equation. The results represent the enthalpic nature of the cooperativity in Hb oxygenation and the compensation effect of intrinsic entropy. The interpretation of results also to be, into account the decrease of the binding affinity of sites for oxygen in the presence of DPG and IHP without any considerable changes in the site-site interaction (extent of cooperativity). In other words, the interactions between bound ligands, organic phosphates and oxygen, are more due to a decreasing binding affinity and not to the reduction of the cooperative interaction between sites. The results also document the more heterotropic effect of IHP compared to DPG.

Extended Oxygen Delivery from the Nerve Hemoglobin ofTellina alternata(Bivalvia)

Science ◽  
1986 ◽  
Vol 232 (4746) ◽  
pp. 90-92 ◽  
Author(s):  
DAVID W. KRAUS ◽  
JAMES M. COLACINO
Keyword(s):  
Carbon Monoxide ◽  
Oxygen Delivery ◽  
Oxygen Removal ◽  
Oxygen Binding ◽  
Considerable Time ◽  
Pure Nitrogen ◽  
Anoxic Conditions ◽  
Neural Excitability ◽  
Aerobic Activity

An oxygen-binding hemoglobin localized in the nerves ofTellina alternata(Bivalvia) required 30 minutes to unload oxygen when excised nerves were exposed to pure nitrogen. Neural excitability under these conditions could be sustained only until deoxygenation of the hemoglobin was complete. When the oxygen-combining function of the hemoglobin was abolished with carbon monoxide, the neural excitability ceased within a few minutes of oxygen removal, a response identical to that of hemoglobinless homologous nerves of other bivalves. These results demonstrate that aerobic activity can be supported by the oxygen stored on hemoglobin in microscopic tissues for a considerable time under anoxic conditions.

scholarly journals Role of Nitric Oxide Carried by Hemoglobin in Cardiovascular Physiology

2020 ◽  
Vol 126 (1) ◽  
pp. 129-158 ◽  
Author(s):  
Richard T. Premont ◽  
James D. Reynolds ◽  
Rongli Zhang ◽  
Jonathan S. Stamler
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Oxygen Delivery ◽  
Tissue Oxygenation ◽  
Common Factor ◽  
Well Being ◽  
Therapeutic Interventions ◽  
Oxygen Binding ◽  
Metabolic Demand ◽  
Hypoxic Vasodilation

A continuous supply of oxygen is essential for the survival of multicellular organisms. The understanding of how this supply is regulated in the microvasculature has evolved from viewing erythrocytes (red blood cells [RBCs]) as passive carriers of oxygen to recognizing the complex interplay between Hb (hemoglobin) and oxygen, carbon dioxide, and nitric oxide—the three-gas respiratory cycle—that insures adequate oxygen and nutrient delivery to meet local metabolic demand. In this context, it is blood flow and not blood oxygen content that is the main driver of tissue oxygenation by RBCs. Herein, we review the lines of experimentation that led to this understanding of RBC function; from the foundational understanding of allosteric regulation of oxygen binding in Hb in the stereochemical model of Perutz, to blood flow autoregulation (hypoxic vasodilation governing oxygen delivery) observed by Guyton, to current understanding that centers on S-nitrosylation of Hb (ie, S-nitrosohemoglobin; SNO-Hb) as a purveyor of oxygen-dependent vasodilatory activity. Notably, hypoxic vasodilation is recapitulated by native S-nitrosothiol (SNO)–replete RBCs and by SNO-Hb itself, whereby SNO is released from Hb and RBCs during deoxygenation, in proportion to the degree of Hb deoxygenation, to regulate vessels directly. In addition, we discuss how dysregulation of this system through genetic mutation in Hb or through disease is a common factor in oxygenation pathologies resulting from microcirculatory impairment, including sickle cell disease, ischemic heart disease, and heart failure. We then conclude by identifying potential therapeutic interventions to correct deficits in RBC-mediated vasodilation to improve oxygen delivery—steps toward effective microvasculature-targeted therapies. To the extent that diseases of the heart, lungs, and blood are associated with impaired tissue oxygenation, the development of new therapies based on the three-gas respiratory system have the potential to improve the well-being of millions of patients.

scholarly journals Haemoglobin-loaded metal organic framework-based nanoparticles camouflaged with a red blood cell membrane as potential oxygen delivery systems

2020 ◽  
Vol 8 (21) ◽  
pp. 5859-5873
Author(s):  
Xiaoli Liu ◽  
Michelle M. T. Jansman ◽  
Leticia Hosta-Rigau
Keyword(s):  
Cell Membrane ◽  
Blood Cell ◽  
Protein Adsorption ◽  
Red Blood Cell ◽  
Oxygen Delivery ◽  
Metal Organic Framework ◽  
Metal Organic Frameworks ◽  
Oxygen Binding ◽  
Metal Organic ◽  
Potential Oxygen

Metal organic frameworks are used to protect hemoglobin from denaturation thus preserving its excellent oxygen-binding and releasing properties. Decorating with cell membranes minimizes protein adsorption holding potential for long circulation.   

Possible Relationship Between Energy Metabolism of Muscle and Oxygen Binding Characteristics of Haemocyanin of Cephalopods

1978 ◽  
Vol 58 (2) ◽  
pp. 421-424 ◽  
Author(s):  
V. A. Zammit
Keyword(s):  
Energy Metabolism ◽  
Ph Sensitive ◽  
Oxygen Binding ◽  
Small Decrease ◽  
Binding Characteristics ◽  
Binding Curve

The pronounced Bohr shift of cephalopod haemocyanin may be related to the formation of octopine, rather than lactate, by cephalopod muscle. Octopine is a much weaker acid than lactate.A highly pH-sensitive oxygen binding curve would permit the efficient unloading of oxygen at the tissues even for a moderately small decrease in venous pH.

scholarly journals Evolutionary and functional insights into the mechanism underlying body-size-related adaptation of mammalian hemoglobin

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Olga Rapp ◽  
Ofer Yifrach
Keyword(s):  
Body Size ◽  
Conformational Changes ◽  
Oxygen Delivery ◽  
Fine Tuning ◽  
Hill Coefficient ◽  
Oxygen Binding ◽  
Tissue Oxygen ◽  
Model Protein ◽  
Tissue Oxygen Delivery ◽  
The Hill

Hemoglobin (Hb) represents a model protein to study molecular adaptation in vertebrates. Although both affinity and cooperativity of oxygen binding to Hb affect tissue oxygen delivery, only the former was thought to determine molecular adaptations of Hb. Here, we suggest that Hb affinity and cooperativity reflect evolutionary and physiological adaptions that optimized tissue oxygen delivery. To test this hypothesis, we derived the relationship between the Hill coefficient and the relative affinity and conformational changes parameters of the Monod-Wymann-Changeux allosteric model and graphed the ‘biophysical Hill landscape’ describing this relation. We found that mammalian Hb cooperativity values all reside on a ridge of maximum cooperativity along this landscape that allows for both gross- and fine-tuning of tissue oxygen unloading to meet the distinct metabolic requirements of mammalian tissues for oxygen. Our findings reveal the mechanism underlying body size-related adaptation of mammalian Hb. The generality and implications of our findings are discussed.

scholarly journals Cardiac myoglobin deficit has evolved repeatedly in teleost fishes

2014 ◽  
Vol 10 (6) ◽  
pp. 20140225 ◽  
Author(s):  
Daniel J. Macqueen ◽  
Daniel Garcia de la serrana ◽  
Ian A. Johnston
Keyword(s):  
Oxygen Delivery ◽  
Evolutionary History ◽  
Full Range ◽  
Mrna Level ◽  
Oxygen Binding ◽  
Teleost Fishes ◽  
Striated Muscles ◽  
Antarctic Icefish ◽  
Common Facet ◽  
The Antarctic

Myoglobin (Mb) is the classic vertebrate oxygen-binding protein present in aerobic striated muscles. It functions principally in oxygen delivery and provides muscle with its characteristic red colour. Members of the Antarctic icefish family (Channichthyidae) are widely thought to be extraordinary for lacking cardiac Mb expression, a fact that has been attributed to their low metabolic rate and unusual evolutionary history. Here, we report that cardiac Mb deficit, associated with pale heart colour, has evolved repeatedly during teleost evolution. This trait affects both gill- and air-breathing species from temperate to tropical habitats across a full range of salinities. Cardiac Mb deficit results from total pseudogenization in three-spined stickleback and is associated with a massive reduction in mRNA level in two species that evidently retain functional Mb. The results suggest that near or complete absence of Mb-assisted oxygen delivery to heart muscle is a common facet of teleost biodiversity, even affecting lineages with notable oxygen demands. We suggest that Mb deficit may affect how different teleost species deal with increased tissue oxygen demands arising under climate change.

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.

The biochemistry of drugs and doping methods used to enhance aerobic sport performance

2008 ◽  
Vol 44 ◽  
pp. 63-84 ◽  
Author(s):  
Chris E. Cooper
Keyword(s):  
Oxygen Uptake ◽  
Oxygen Content ◽  
Oxygen Delivery ◽  
Sport Performance ◽  
Blood Substitutes ◽  
Altitude Training ◽  
Blood Oxygen ◽  
Oxygen Carriers ◽  
Sports Performance ◽  
Blood Doping

Optimum performance in aerobic sports performance requires an efficient delivery to, and consumption of, oxygen by the exercising muscle. It is probable that maximal oxygen uptake in the athlete is multifactorial, being shared between cardiac output, blood oxygen content, muscle blood flow, oxygen diffusion from the blood to the cell and mitochondrial content. Of these, raising the blood oxygen content by raising the haematocrit is the simplest acute method to increase oxygen delivery and improve sport performance. Legal means of raising haematocrit include altitude training and hypoxic tents. Illegal means include blood doping and the administration of EPO (erythropoietin). The ability to make EPO by genetic means has resulted in an increase in its availability and use, although it is probable that recent testing methods may have had some impact. Less widely used illegal methods include the use of artificial blood oxygen carriers (the so-called ‘blood substitutes’). In principle these molecules could enhance aerobic sports performance; however, they would be readily detectable in urine and blood tests. An alternative to increasing the blood oxygen content is to increase the amount of oxygen that haemoglobin can deliver. It is possible to do this by using compounds that right-shift the haemoglobin dissociation curve (e.g. RSR13). There is a compromise between improving oxygen delivery at the muscle and losing oxygen uptake at the lung and it is unclear whether these reagents would enhance the performance of elite athletes. However, given the proven success of blood doping and EPO, attempts to manipulate these pathways are likely to lead to an ongoing battle between the athlete and the drug testers.

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