scholarly journals Net charge and oxygen affinity of human hemoglobin are independent of hemoglobin concentration.

1978 ◽  
Vol 72 (6) ◽  
pp. 765-773 ◽  
Author(s):  
G Gros ◽  
H S Rollema ◽  
W Jelkmann ◽  
H Gros ◽  
C Bauer ◽  
...  
Keyword(s):  
Ionic Strength ◽  
Functional Properties ◽  
Ph Value ◽  
Oxygen Affinity ◽  
Hemoglobin Concentration ◽  
Human Hemoglobin ◽  
Hemoglobin Solution ◽  
Net Charge ◽  
Oxygen Concentrations

The dependence of net charge and oxygen affinity of human hemoglobin upon hemoglobin concentration was reinvestigated. In contrast to earlier reports from various laboratories, both functional properties of hemoglobin were found to be independent of hemoglobin concentration. Two findings indicate a concentration-independent net charge of carbonmonoxy hemoglobin at pH 6.6: (A) The pH value of a given carbonmonoty hemoglobin solution remains constant at 6.6 when the hemoglobin concentration is raised from 10 to 40 g/dl, indicating that there is no change in protonation of titratable groups of hemoglobin: (b) the net charge of carbonmonoxy hemoglobin as estimated from the Donnan distribution of 22Na+ shows no dependence on hemoglobin concentration in this concentration range. The oxygen affinity of human hemoglobin was determined from measurements of oxygen concentrations in equilibrated samples using a Lex-O2-Con apparatus (Lexington Instruments, Waltham, Mass.). P50 averaged 11.4 mm Hg at 37 degrees C, pH = 7.2, and ionic strength approximately 0.15. Neither P50 nor Hill's n showed any variation with hemoglobin concentrations increasing from 10 to 40 g/dl.

scholarly journals Hemoglobin Andrew-Minneapolis αA2β144 Lys → Asn2: A New High-Oxygen-Affinity Mutant Human Hemoglobin

Blood ◽  
1974 ◽  
Vol 44 (4) ◽  
pp. 543-549 ◽  
Author(s):  
Solomon J. Zak ◽  
Bernadine Brimhall ◽  
Richard T. Jones ◽  
Manuel E. Kaplan
Keyword(s):  
Functional Properties ◽  
Primary Structure ◽  
Whole Blood ◽  
Autosomal Dominant ◽  
Oxygen Affinity ◽  
High Oxygen ◽  
Human Hemoglobin ◽  
High Oxygen Affinity ◽  
Dominant Characteristic ◽  
Β Chain

Abstract The functional properties and primary structure of a new β-chain mutant of human hemoglobin are described. The mutant was transmitted as an autosomal dominant characteristic. Affected members of the kindred exhibited marked erythrocytosis due to the high oxygen affinity of the resultant hemoglobin. The abnormality is associated with a substitution of an asparaginyl residue for lysine in the 144 position of the β-chain, αA2β144Lys→Asn2, presumably due to an AAA/G to AAA/U transversion. The mutant hemoglobin displayed a profound increase in oxygen affinity, with a P50 of the fresh whole blood of 14 mm Hg. The isolated mutant hemoglobin exhibited near normal heme—heme interaction, a half-normal Bohr effect, and normal reactivity with 2,3-diphosphoglycerate.

Donnan Equilibria in Polymeric Micellar Systems with Weak Polyelectrolyte Shells: The Lowering of the pH Value

1997 ◽  
Vol 62 (11) ◽  
pp. 1730-1736 ◽  
Author(s):  
Petr Munk ◽  
Zdeněk Tuzar ◽  
Karel Procházka
Keyword(s):  
Ionic Strength ◽  
Block Copolymer ◽  
Ph Value ◽  
Electrolyte Solutions ◽  
Hydrogen Ions ◽  
Micellar Systems ◽  
Weak Electrolytes ◽  
Block Copolymer Micelles ◽  
Copolymer Micelles ◽  
Polyelectrolyte Solutions

When two electrolyte solutions are separated and only some of the ions can cross the boundary, the concentrations of these ions are different on both sides of the boundary. This is the well-known Donnan effect. When weak electrolytes are involved, the imbalance includes also hydrogen ions: there is a difference of pH across the boundary and the dissociation of nondiffusible weak electrolytes is suppressed. The effect is very pronounced when the concentration of the weak electrolyte is high and ionic strength is low. The significance of this phenomenon is discussed for polyelectrolyte solutions, and particularly for block copolymer micelles with weak polyelectrolyte shells. The effect is quite dramatic in the latter case.

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.

scholarly journals Effect of X-rays on structural, physicochemical and functional properties of gluten protein

2021 ◽  
Vol 24 ◽  
Author(s):  
Durga Chandra ◽  
Ashish Dabade ◽  
Gauri Damgude ◽  
Chetali Malhotra
Keyword(s):  
Functional Properties ◽  
Water Solubility ◽  
Stability Index ◽  
Time Range ◽  
Gluten Protein ◽  
X Rays ◽  
Net Charge ◽  
Emulsification Activity ◽  
X Ray ◽  
Sds Page

Abstract The gluten protein was exposed to the X-ray radiations for different time range, comprising 1 and 3 seconds. The objective of this study was to determine the effect of x-ray radiations on the physicochemical properties of gluten protein. Different functional properties of proteins like water and oil holding capacities, protein solubility, emulsification activity, and stability index, foaming action and stability, water solubility, protein, and moisture content, along with SDS PAGE, FTIR, Xeta potential net charge was carried out to evaluate the effect of X-ray radiation on gluten protein. Results showed that the enhancement of water holding capacity up to 38.12%, as well as oil holding capacity up to 35% could be seen, whereas a significant decrease in emulsification activity and stability index, foaming capacity and stability, even protein content could be observed in treated samples. The net charge on protein in water solution was found to increase towards the positive side. The structure of the protein remained unchanged based on no change was observed in SDS PAGE electrograph, FTIR secondary structure region. Hence, X-ray treatment can be a possible way to alter the protein structure for “tailor-made applications” in food industries.

scholarly journals Evaluation of NaCl and KCl Salting Effects on Technological Properties of Pre- and Post-Rigor Chicken Breasts at Various Ionic Strengths

Foods ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 721
Author(s):  
Dong-Heon Song ◽  
Youn-Kyung Ham ◽  
Sin-Woo Noh ◽  
Koo Bok Chin ◽  
Hyun-Wook Kim
Keyword(s):  
Ionic Strength ◽  
Ph Value ◽  
Protein Solubility ◽  
Textural Properties ◽  
Myofibrillar Protein ◽  
Cooking Loss ◽  
Technological Properties ◽  
Raw Meat

The objective of this study is to evaluate the effects of NaCl and KCl salting on technological properties of pre- and post-rigor chicken breasts at various ionic strengths. The following factorial arrangement was used: 2 salt types (NaCl and KCl) × 2 rigor statuses (pre- and post-rigor) × 4 ionic strengths (0.086, 0.171, 0.257, and 0.342). Hot-boned and ground chicken breasts were salted within 30 min postmortem after slaughter (pre-rigor salting) or 24 h postmortem (post-rigor salting) with varying concentrations of NaCl (0.50%, 1.00%, 1.50%, and 2.00%) or KCl (0.64%, 1.28%, 1.91%, and 2.55%) corresponding to the four ionic strengths. KCl caused higher pH value in salted chicken breasts than NaCl (p < 0.05). However, KCl decreased total and myofibrillar protein solubilities in post-rigor salted chicken breasts compared to NaCl (p < 0.05), but those were similar to pre-rigor chicken breasts, regardless of the salt type (p > 0.05). Different salt types had no significant impact on cooking loss and textural properties. This study shows that NaCl and KCl had similar effects on technological properties at the same ionic strength (within 0.342), but the use of KCl may have the possibility to decrease protein solubility, depending on rigor status of raw meat at the different salting time.

scholarly journals Adsorption behavior of diclofenac-containing wastewater on three kinds of sewage sludge

2019 ◽  
Vol 80 (4) ◽  
pp. 717-726 ◽  
Author(s):  
Jingna Yan ◽  
Xiaohan Zhang ◽  
Wenting Lin ◽  
Chen Yang ◽  
Yuan Ren
Keyword(s):  
Ionic Strength ◽  
Adsorption Isotherm ◽  
Wastewater Treatment Plants ◽  
Ph Value ◽  
Water Environment ◽  
Organic Matter Content ◽  
Matter Content ◽  
Isotherm Models ◽  
Treatment Unit ◽  
Pseudo Second Order

Abstract Diclofenac (DCF) is one of the most frequently detected non-steroidal anti-inflammatory drugs (NSAIDs) in the water environment. One of the main removal routes of DCF in wastewater is sludge adsorption, and the mechanisms need to be investigated. In this study, the effects of adsorption time, temperature, pH value, and ionic strength on the adsorption of DCF on suspended particles (SP), secondary sedimentation tank sludge (SSTS) and concentrated sludge (CS) were investigated. The results showed that most of the adsorption of DCF by the three matrices was conducted in the first 4 h and equilibrium was achieved at 8 h. The adsorption kinetics were well fitted with the pseudo-second-order model and the rate constants were 0.29–0.88 mg·(μg·min)−1, with chemical adsorption as the dominant one. Adsorption isotherm conformed to Freundlich, Langmuir and Linear adsorption isotherm models. The order of adsorption capacity was: CS &gt; SSTS &gt; SP, which was proportional to the organic matter content and specific surface area of the adsorbents. The decrease of the pH value and the increase of ionic strength promoted the adsorption of DCF. The results can provide data support for the removal of DCF from different treatment unit types in wastewater treatment plants.

Oxygen-linked CO2 transport in sheep blood

1975 ◽  
Vol 229 (2) ◽  
pp. 334-339 ◽  
Author(s):  
R Bauman ◽  
C Bauer ◽  
EA Haller
Keyword(s):  
Whole Blood ◽  
Oxygen Affinity ◽  
Hemoglobin Concentration ◽  
Cell Suspensions ◽  
Bohr Effect ◽  
Carbon Dioxide Exchange ◽  
Red Cell ◽  
Sheep Blood ◽  
Sheep Hemoglobin ◽  
Binding Curves

We have analyzed oxygen-linked carbamate formation in sheep hemoglobin B by measuring a) the effect of CO2 on oxygen affinity and Bohr effect in red cell suspensions and dilute (1.3 mM Hb4) and concentrated (5 mM Hb4) hemoglobin solutions at 37 degrees C and b) CO2 binding curves of deoxygenated and oxygenated whole blood and hemoglobin solutions, respectively, at the same temperature. In the presence of CO2 both the Bohr effect and oxygen affinity were significantly lower in 1.3-mM Hb4 solutions than in either red cell suspensions or 5-mM Hb4 solutions, while in the absence of CO2 Bohr effect and oxygen affinity did not differ significantly in those preparations. Likewise, the fraction of oxygen-linked carbamate obtained from CO2 binding curves was found to be higher in 1.3-mM Hb4 (0.156 M HbCO2/M HbO2) solutions than in 5-mM Hb4 solutions (0.12 M HbCO2/M HbO2) at pH 7.2. We conclude that hemoglobin concentration affects formation of oxygen-linked carbamate. Total oxygen-linked CO2 in sheep whole blood amounted to 0.18 M CO2/M O2 of which 70% is oxygen-linked carbamate. Assuming a respiratory quotient of 0.85, the contribution of oxygen-linked CO2 to carbon dioxide exchange in sheep blood was computed to be 21%.

scholarly journals Oxygen affinity of blood in altitude Sherpas

1979 ◽  
Vol 47 (2) ◽  
pp. 337-341 ◽  
Author(s):  
M. Samaja ◽  
A. Veicsteinas ◽  
P. Cerretelli
Keyword(s):  
Sea Level ◽  
Concentration Ratio ◽  
Oxygen Affinity ◽  
Hemoglobin Concentration ◽  
Cell Counts ◽  
Blood Cell Counts ◽  
Total Hemoglobin ◽  
The Mean ◽  
Total Hemoglobin Concentration ◽  
2,3 Dpg

Oxygen equilibrium curves on blood within 6 h from sampling have been estimated from polarographic measurements of oxyhemoglobin concentration, in 13 male 14- to 50-yr old Sherpas residing at 3,850 m above sea level (Kumjung, Nepal). In samples with red blood cell counts = 4.7 +/- 0.8 (SD) x 10(6)/mm3, total hemoglobin concentration [Hb] = 17.0 +/- 1.9 g/dl, and hematocrit = 53.3 +/- 5.0, the mean oxygen half-saturation of hemoglobin (P50) (pH = 7.4 and PCO2 = 40 Torr) was 27.3 +/- 1.8 Torr. The P50 of altitude Sherpas was not significantly different from that of acclimatized lowlanders (28.2 +/- 1.3; n = 7), sea-level Caucasian residents (26.5 +/- 1.0; n = 17), and Sherpas at sea level (27.1; n = 3). The 2,3-diphosphoglyceric acid-to-hemoglobin concentration ratio ([2,3-DPG]/[Hb]) in altitude Sherpas was 1.22 +/- 0.03, the same as that of acclimatized Caucasians (1.22 +/- 0.10). The Bohr effect measured for the blood of one altitude Sherpas by the ratio deltalog P50/deltapH was -0.32 and -0.45 at PCO2 levels of 40 and 20 Torr, respectively. These values are not significantly different from those found in Caucasians at sea level where deltalog P50/deltalpH was -0.35 and -0.42, respectively. It is concluded that the P50 in native highlanders is not significantly different from that observed in sea-level dwellers. [2,3-DPG]/[Hb] at altitude, both in natives and in newcomers, is 20% higher than in sea-level residents.

Oxygen dependence of redox state of copper in cytochrome oxidase in vitro

1993 ◽  
Vol 74 (4) ◽  
pp. 1622-1627 ◽  
Author(s):  
Y. Hoshi ◽  
O. Hazeki ◽  
M. Tamura
Keyword(s):  
Respiratory Rate ◽  
Cytochrome Oxidase ◽  
Near Infrared ◽  
Energy State ◽  
Oxygen Affinity ◽  
Quantitative Information ◽  
Low Oxygen ◽  
Straight Line ◽  
Oxygen Concentrations

To obtain quantitative information about tissue oxygenation from near-infrared signals, the oxygen dependencies of the redox states of both heme a+a3 and copper in cytochrome oxidase of isolated mitochondria were determined at low oxygen concentrations (10(-6)-10(-9) M) using leghemoglobin as an oxygen indicator. The maximum absorbance changes caused by the aerobic-anaerobic transition measured at 830–760 nm of copper in state 3, state 4, and the uncoupled state were 10, 17, and 5% of those at 605–620 nm of heme a+a3, respectively. Thus the relative absorbance ratio of copper to heme a+a3 could be used as a sensitive indicator for the mitochondrial energy state. The oxygen concentrations required for the half-maximal reduction of heme a+a3 varied with the energy state and the respiratory rate and were 7.8 x 10(-8) and 1.6 x 10(-7) M in state 4 and state 3, respectively. In contrast, that of copper was 7.5 x 10(-8) M and was independent of both the energy state and the respiratory rate. The relationship between the percent oxidation of heme a+a3 and copper in the aerobic-anaerobic transition did not show a straight-line relationship. This was referred to as the difference in oxygen affinity between these two chromophores. The deviation from the straight line was larger in state 3 than in state 4.(ABSTRACT TRUNCATED AT 250 WORDS)

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