Haemocyanin oxygen binding and the physiological ecology of a range of talitroidean amphipods (Crustacea) II. Effect of freezing, inorganic ions, and urate on O2 binding in vitro

1991 ◽  
Vol 161 (2) ◽  
Author(s):  
JohnI. Spicer ◽  
BrianR. McMahon
Keyword(s):  
Physiological Ecology ◽  
Inorganic Ions ◽  
Oxygen Binding ◽  
O2 Binding

Responses to Hypersaline Exposure in the Euryhaline Crayfish PAcifastacus Leniusculus: II. Modulation of Haemocyanin Oxygen Binding In Vitro and In Vivo

1982 ◽  
Vol 99 (1) ◽  
pp. 447-467
Author(s):  
MICHÈLE G. WHEATLY ◽  
B. R. MCMAHON
Keyword(s):  
Salt Effect ◽  
Ionic Composition ◽  
Inorganic Ions ◽  
Pacifastacus Leniusculus ◽  
Oxygen Binding ◽  
Complete Saturation ◽  
O2 Delivery ◽  
O2 Binding

The effect of 48 h of hypersaline exposure (25, 50 and 75% SW) on haemocyanin oxygenation properties in the euryhaline crayfish Pacifastacus leniusculus was investigated in vitro and in vivo. In vitro significant increases in affinity and cooperativity were measured, although the magnitude of the Bohr shift was unaffected. In vitro dialysis of haemolymph against physiological salines of variable ionic composition proved that these changes were only partly attributable to altered levels of haemolymph ions, implicating the existence of modulators other than H+ and inorganic ions, the possible identities of which are discussed. Significant depressions of both pre- and postbranchial oxygen tensions (Pv, Ov, O2 and Pa, Oa, O2) were observed, but O2 delivery was maintained by utilization of the venous reserve and by an increase in haemocyanin O2 affinity. This occurred despite a concomitant acidosis whose effect on O2 affinity was directly opposed by the ‘salt’ effect. Under hypersaline conditions, haemocyanin played an increasingly important role in O2 delivery in vivo. Despite a reduction in the concentration of combined O2 at complete saturation of the pigment (CmaxHCyOHCyO2). indicating lowered haemocyanin concentration, compensatory changes in O2-binding and cardiac output precluded an impairment to O2 transfer. Equilibration at the tissues (Et,Ot,O2) in FW was less effective than at the gills (Eb,Ob,O2 but progressively improved with hypersaline exposure reversing this trend. Although effects of increased salinity on O2 equilibrium characteristics were qualitatively similar in vivo and in vitro, some interesting quantitative differences are discussed.

scholarly journals Seminal Plasma: Relevant for Fertility?

2021 ◽  
Vol 22 (9) ◽  
pp. 4368
Author(s):  
Heriberto Rodriguez-Martinez ◽  
Emilio A. Martinez ◽  
Juan J. Calvete ◽  
Fernando J. Peña Vega ◽  
Jordi Roca
Keyword(s):  
Seminal Plasma ◽  
Current Knowledge ◽  
Inorganic Ions ◽  
Vitro Fertilization ◽  
Dna And Rna ◽  
Model Animal ◽  
Sexual Glands ◽  
Species Specific

Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual glands. Its composition, despite species-specific anatomical peculiarities, consistently contains inorganic ions, specific hormones, proteins and peptides, including cytokines and enzymes, cholesterol, DNA and RNA—the latter often protected within epididymis- or prostate-derived extracellular vesicles. It is beyond question that the SP participates in diverse aspects of sperm function pre-fertilization events. The SP also interacts with the various compartments of the tubular genital tract, triggering changes in gene function that prepares for an eventual successful pregnancy; thus, it ultimately modulates fertility. Despite these concepts, it is imperative to remember that SP-free spermatozoa (epididymal or washed ejaculated) are still fertile, so this review shall focus on the differences between the in vivo roles of the SP following semen deposition in the female and those regarding additions of SP on spermatozoa handled for artificial reproduction, including cryopreservation, from artificial insemination to in vitro fertilization. This review attempts, including our own results on model animal species, to critically summarize the current knowledge of the reproductive roles played by SP components, particularly in our own species, which is increasingly affected by infertility. The ultimate goal is to reconcile the delicate balance between the SP molecular concentration and their concerted effects after temporal exposure in vivo. We aim to appraise the functions of the SP components, their relevance as diagnostic biomarkers and their value as eventual additives to refine reproductive strategies, including biotechnologies, in livestock models and humans.

PRO-INFLAMMATORY MOLECULAR AND INFLAMMATORY MECHANISMS OF SULFUR METABOLISM IN IBD-RELEVANT CLOSTRIDIA SPECIES

2021 ◽  
Vol 27 (Supplement_1) ◽  
pp. S30-S31
Author(s):  
Gabriel Suarez ◽  
Bo Liu ◽  
Jeremy Herzog ◽  
Ryan Sartor
Keyword(s):  
Sulfur Metabolism ◽  
Cellular Respiration ◽  
Bile Acid Metabolism ◽  
Bile Salt Hydrolase ◽  
Oxygen Binding ◽  
Bacterial Strains ◽  
Healthy Human ◽  
H2s Production

Abstract Sulfur metabolism is emerging as a signature of IBD gut microbiota. Overrepresentation of sulfur-reducing bacteria (SRB) in IBD results in SRB-derived epithelial toxic H2S production that can overwhelm the body’s detoxification capacity, leading to impaired cellular respiration by inhibiting oxygen binding to mitochondrial cytochrome-c-oxidase. Butyrate potently inhibits SRBs and H2S, yet IBD patients have reduced short chain fatty acid (SCFA) production. More critically, H2S blocks butyrate oxidation, the primary energy source of colonocytes; butyrate oxidation deficiency is a defining characteristic of IBD. Since cysteine is the preferred substrate for H2S production by SRBs, a cysteine-rich environment provided by either a high protein diet or local intestinal mucus degradation promotes ideal conditions for SRB establishment and proliferation. SRBs can catabolize other sulfur-containing compounds critical for immune homeostasis and cellular health, such as taurine-conjugated bile acids and the “master antioxidant” glutathione, leading to further toxic H2S production. However, the molecular underpinnings of sulfur metabolism by specific bacterial genera is understudied in IBD. Results: Using a combination of in-vivo and in-vitro screening to detect the relative induction of interleukin 10 (IL-10) and interferon g (IFNg) by 19 resident bacterial strains isolated from a healthy human donor, we identified 4 bacterial strains that induce a low IL-10/IFNg ratio. These 4 strains (low group), but not 3 bacterial strains that induce a high IL-10/IFNg ratio, induce colitis in selectively colonized gnotobiotic Il10-/- mice (Fig.1A). Two of these 4 disease-inducing strains, Clostridium perfringens (A12) and Clostridium bolteae (B6), produce high concentrations of H2S in monoassociated mice (Fig.1B). In-vitro H2S production by these strains is dependent on cysteine (Fig.1C). C. perfringens and C. bolteae each induce colitis in monoassociated Il10-/- mice (Fig.1D). We are dissecting the sulfur metabolic pathways in C. perfringens and C. bolteae and their contribution to inflammatory processes by interrupting key genes predicted to contribute to H2S production, cysteine catabolism and bile acid metabolism. We will use these mutants in both in-vitro and in-vivo Il10 -/- gnotobiotic mice models to characterize their metabolic and inflammatory profiles. We have created several mutants using Targetron gene editing, including the dissimilatory sulfate reductase (Δdsr), a putative sulfonate membrane transporter (ΔssuA), anaerobic sulfite reductase (ΔasrA) and bile salt hydrolase (Δbsh). Conclusions: H2S producing bacterial strains can induce experimental colitis. Our planned mechanistic studies will determine the metabolic routes for H2S production by specific aggressive bacteria to guide novel therapeutic or dietary interventions to improve IBD prognosis.

Self-association, cooperativity and supercooperativity of oxygen binding by hemoglobins.

1998 ◽  
Vol 201 (8) ◽  
pp. 1073-1084 ◽  
Author(s):  
A F Riggs
Keyword(s):  
Muscle Tissue ◽  
Buoyant Density ◽  
Fold Increase ◽  
Heme Iron ◽  
Common Mechanism ◽  
Oxygen Binding ◽  
Hypoxic Environment ◽  
Self Association ◽  
The Stability ◽  
O2 Binding

Cooperative ligand binding by tetrameric vertebrate hemoglobins (Hbs) makes possible the delivery of oxygen at higher pressures than would otherwise occur. This cooperativity depends on changes in dimer-dimer interactions within the tetramer and is reflected in a 50 000-fold increase in the tetramer-dimer dissociation constant in human Hb upon oxygenation at pH 7.4, from approximately 2x10(-11)mol l-1 to approximately 10(-6)mol l-1. Hbs that undergo such ligand-dependent changes in association are widespread in non-vertebrates, where the mechanisms are very different from those in vertebrates. Oligomeric Hbs have been identified in organisms in five phyla (molluscs, echinoderms, annelids, phoronids and chordates) that dissociate to subunits upon oxidation of the heme iron and reassociate with the binding of ferric iron ligands such as CN-, N3- or NO2-. Thus, the valence and ligand state of the heme iron control the stability of a critical subunit interface. The broad distribution of this phenomenon suggests a common mechanism of communication between heme and interface that may be almost universal among non-vertebrate Hbs. This interaction may be similar to that known for the homodimeric Hb of the mollusc Scapharca inaequivalvis. Although muscle tissue Hbs or myoglobins (Mbs) are usually monomeric, with non-cooperative O2 binding, the radular muscles of gastropod molluscs and chitons have homodimeric Mbs that bind O2 cooperatively. Cooperative non-muscle tissue Hbs have also been identified. These include the neural Hb of the nemertean worm Cerebratulus lacteus and the Hb of the diving beetle Anisops assimilis, which exhibit deoxygenation-dependent self-association of monomers that is associated with high Hill coefficients. Calculations suggest that the 2-3 mmol l-1 concentration of Hb on a heme basis in the brain of Cerebratulus should substantially extend the time as an active predator in an anaerobic or hypoxic environment. Oxygen from the Hb of Anisops is delivered to a gas bubble and thereby controls the buoyant density. Many Hbs of amphibians, reptiles, birds and some embryonic mammals exhibit a further 'supercooperativity' of O2 binding which depends on reversible deoxygenation-dependent tetramer-tetramer association to form an assemblage with a very low affinity for O2. This phenomenon results in steeper O2-binding curves than exhibited by tetramers alone. The increased cooperativity should result in an increase in the amount of O2 delivered to the tissues and should be especially valuable for avian flight muscles.

Development of a Triazolyldisulfide Compound That Increases the Affinity of Hemoglobin for Oxygen and Reduces Hypoxic Sickling of Sickle Cells

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3642-3642 ◽  
Author(s):  
Akito Nakagawa ◽  
Ferrari Michele ◽  
Chen Liu ◽  
Lorenzo Berra ◽  
Elizabeth S. Klings ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Patent Application ◽  
Thiol Group ◽  
Time Dependent ◽  
Oxygen Binding ◽  
Cell Disease ◽  
Dependent Change ◽  
Time Dependent Change

Abstract Introduction: In patients with sickle cell disease,during a vasoocclusive crisis, deoxygenated sickle hemoglobin (HbS) polymerizes forming fibers of HbS in red blood cells (SS RBCs). HbS fibers distort SS RBCs, causing microvascular occlusion, increased thrombosis and inflammation, and severe pain for patients. Increasing the affinity of Hb for oxygen reduces sickling of SS RBCs, because oxygenated HbS does not form polymers. It has been reported that modification of the thiol group of Hb β-Cys93 increases Hb's affinity for oxygen by destabilizing the T-state and stabilizing the R-state. In addition, modification of HbS β-Cys93 might prevent interaction between HbS molecules and thereby reduce sickling. Herein we report a novel triazolyldisulfide compound (4,4'-Di(1,2,3-triazolyl)disulfide, designated "TD-3"), which increases the affinity of Hb for oxygen and reduces the sickling of hypoxic human SS RBCs in vitro. Intravenous administration of TD-3 to mice increases the affinity of murine Hb for oxygen. The effects of TD-3 on the affinity of Hb for oxygen may be a result of interaction with HbA-Cys93. Methods: TD-3 hydrate was dissolved in a mixture of Dulbecco's phosphate buffered saline and 30% polyethylene glycol 400. The oxygen dissociation curve (ODC) of Hb was measured at 37°C (pH 7.3) using a HEMOX analyzer. The partial oxygen pressure at which 50% of Hb is oxygenated was determined as P50 from the ODC and the P50 was used to assess the affinity of Hb for oxygen. SS whole blood was incubated with TD-3 (Hb tetramer/TD-3 = 1/1 mol/mol) for 10 min at 37°C and the P50 of TD-3 treated RBCs was determined. To evaluate the ability of TD-3 to reduce sickling in vitro, SS RBCs (Hct ≈ 20%) were incubated with TD-3 in a gas mixture of 4% oxygen and 96% nitrogen and the percentage of sickled RBCs was determined after incubation. To determine the effect of TD-3 on time-dependent change of P50 in vitro, normal human whole blood (Hct ≈ 45-50%) was incubated with TD-3 (Hb tetramer/TD-3 = 1/1 mol/mol) for 10 min and 8 h at 37°C. At both times, the P50 of RBCs was determined. To determine the effect of TD-3 on the time-dependent change of P50 in vivo, TD-3 (100 mg/kg) was administered intravenously to C57BL/6 mice and the P50 of murine Hb was determined (as hemolysate) before, and 1 and 24 h after TD-3 treatment. As a first step to investigate the mechanism of action of TD-3, normal adult hemoglobin (HbA) was treated with N-ethylmaleimide (NEM) to block HbA β-Cys93 and the P50 of NEM-treated HbA was determined. Either HbA or NEM-treated HbA was incubated with TD-3 at 37°C for 10 min (Hb tetramer/TD-3 = 1/6 mol/mol). After the incubation, the P50 of HbA and NEM-treated HbA was determined. Results: Incubation of TD-3 with SS RBCs reduced the P50 of SS RBCs from 29 mmHg to 24 mmHg. Incubation of SS RBCs with TD-3 (2 mM) in 4% oxygen decreased the percentage of sickled RBCs from 94% (without TD-3) to 22%. The P50 of TD-3-treated human normal RBCs was decreased from 25 mmHg (prior to adding TD-3) to 21 mmHg at 10 min. At 8 h, the P50 of TD-3-treated human normal RBCs was the same as that of RBCs treated with vehicle alone. The P50 of TD-3-treated murine Hb was reduced from 21 mmHg (before treatment with TD-3) to 18 mmHg at 1 h. At 24 h, the P50 of TD-3-treated murine Hb was the same as that of mice treated with vehicle alone. At 24 h, all of the mice that were treated with either TD-3 or vehicle alone were alive and appeared normal. Treatment of HbA with NEM reduced the P50 from 17 mmHg to 8 mmHg. Incubation of TD-3 with either HbA or NEM-treated HbA reduced the P50 of HbA from 17 mmHg to 4 mmHg, but did not alter the P50 of NEM treated HbA (8 mmHg). Conclusions: 4,4'-Di(1,2,3-triazolyl)disulfide (TD-3) increased the affinity of human normal and SS RBCs for oxygen and reduced the sickling of hypoxic human SS RBCs in vitro. Administration of TD-3 to healthy mice increased the affinity of murine Hb for oxygen and the compound was well tolerated by the mice. The effect of TD-3 on the affinity of HbA for oxygen was impaired by blocking the thiol group of HbA β-Cys93 with NEM, suggesting that the mechanism by which TD-3 increases the affinity of Hb for oxygen and reduces sickling may be through interaction with Hb β-Cys93. Our data demonstrate that TD-3 has the potential to prevent and treat sickle cell disease. Disclosures Nakagawa: Massachusetts General Hospital: Patents & Royalties: MGH filed a patent application on the use of heteroaryl disulfide compounds including TD-3 to increase the oxygen-binding affinity of hemoglobin and treat sickle cell disease and other uses of these compounds. The patent hasn't issued or licensed yet.. Zapol:Massachusetts General Hospital: Patents & Royalties: MGH filed a patent application on the use of heteroaryl disulfide compounds including TD-3 to increase the oxygen-binding affinity of hemoglobin and treat sickle cell disease and other uses of these compounds. The patent hasn't issued or licensed yet..

scholarly journals Equilibrium and kinetic studies of oxygen binding to fragments of Lymnaea stagnalis (freshwater snail) haemocyanin obtained by proteolytic digestion

1983 ◽  
Vol 209 (2) ◽  
pp. 519-526 ◽  
Author(s):  
A Dawson ◽  
E J Wood
Keyword(s):  
Lymnaea Stagnalis ◽  
Functional Unit ◽  
Polyacrylamide Gel Electrophoresis ◽  
Kinetic Studies ◽  
Freshwater Snail ◽  
Dissociation Rate ◽  
Exchange Chromatography ◽  
Hill Coefficient ◽  
Oxygen Binding ◽  
O2 Binding

Functional fragments of the haemocyanin from the gastropod mollusc Lymnaea stagnalis (freshwater snail) were obtained by partial digestion with trypsin and plasmin. The fragments were purified by ion-exchange chromatography and characterized by detergent/polyacrylamide-gel electrophoresis and crossed immunoelectrophoresis. Three types of single-functional unit fragment were isolated from the trypsin digest, and two immunologically distinct three-functional unit fragments and a single-functional unit fragment were isolated from the plasmin digest. The O2-binding behaviour of the fragments was investigated by equilibrium and kinetic methods. Over the pH range 7.0-8.2, in the presence of 10-20 mM-CaCl2, all of the single-functional unit fragments displayed non-co-operative O2 binding and showed no evidence of a Bohr or a salt effect. A Hill coefficient of less than 1.0 was obtained with one of the two three-functional unit fragments studied, whereas both of these fragments displayed a Bohr effect. Functional heterogeneity of the fragments was indicated by the variation in the O2 affinity, the P50 (partial pressure of O2 at half saturation) ranging between 0.26 and 0.77 kPa (approx. 2-6 mmHg). Stopped-flow data reflected the O2 equilibrium behaviour. Thus there was a fall in the value of the O2 dissociation rate constant from approx. 15 to 1s-1 in parallel with the increase in O2 affinity.

Macromolecular crowding and confinement in cells exposed to hypertonicity

1994 ◽  
Vol 266 (4) ◽  
pp. C877-C892 ◽  
Author(s):  
M. M. Garner ◽  
M. B. Burg
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Cell Volume Regulation ◽  
Macromolecular Crowding ◽  
Inorganic Ions ◽  
Organic Osmolytes ◽  
Osmotic Regulation ◽  
Molecular Crowding ◽  
In Cells

The nonideal properties of solutions containing high concentrations of macromolecules can result in enormous increases in the activity of the individual macromolecules. It has been proposed that molecular crowding and confinement occur in cells and are major determinants of the activity of the proteins and other intracellular macromolecules. This concept has important implications for cell volume regulation because, under crowded conditions, relatively small changes in concentration, consequent to alterations of water content, lead to large changes in macromolecular activity. This review considers several aspects of macromolecular crowding and confinement, including: 1) the physical chemical principles involved; 2) in vitro demonstrations of the effects; 3) relation to water activity; 4) estimates of the actual intracellular activity of water and macromolecules; 5) relation to osmotic regulation in various types of cells, including bacteria, red blood cells, and complex nucleated cells; and 6) the relation to inorganic ions and organic osmolytes in cells stressed by hypertonicity. We conclude that, while there is compelling evidence for important effects of molecular crowding in vitro and in red blood cells, the role of macromolecular crowding and confinement in osmotic regulation of more complex cells is an open question that deserves the extensive attention it is currently receiving.

Bone Bonding of Biomaterials And Apatite Formation On Biomaterials

1999 ◽  
Vol 599 ◽  
Author(s):  
Takashi Nakamura ◽  
Masashi Neo ◽  
Tadashi Kokubo
Keyword(s):  
Bonding Strength ◽  
Bone Cells ◽  
Bone Marrow Cells ◽  
Inorganic Ions ◽  
Apatite Layer ◽  
Apatite Formation ◽  
Bioactive Ceramics ◽  
Transmission Electron ◽  
Bone Apatite

AbstractBioactive ceramics are known, which can bind bone tissue chemically. The authors tested bone-bonding strength of biomaterials using detaching test and observed the interface between bone and bioactive ceramics with transmission electron microscopy. An intervening apatite layer was observed at the interface of bone and bioactive ceramics. This layer was distinguished from bone apatite or ceramic. This apatite layer was formed within several days after implantation before bone was observed on the materials. Bisphosphonate is well known to inhibit apatite formation. The injection of bisphosphonate to rabbits concentrationdependently decreased bone-bonding strength of ceramics. The apatite layer was formed on bioactive ceramics in vitro by immersing them in simulated body fluid that contained similar concentrations of inorganic ions as plasma did. Using this apatite layer formed in vitro, it is possible to characterize the apatite layer. This apatite layer enhanced the differentiation of rat bone marrow cells to bone cells in vitro. When osteoclasts were cultured on this layer, they absorbed the apatite layer.These results suggested this apatite layer not only plays a key role for bone bonding but also behaved as bone-like tissues.

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