The Thermodynamic and Binding Studies of Hg+2 Ions with Egg Protein by Polarographic and pH Metric Techniques

2019 ◽  
Vol 233 (8) ◽  
pp. 1073-1090 ◽  
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma
Keyword(s):  
Protein Molecule ◽  
Binding Studies ◽  
Temperature Dependent ◽  
Ph Values ◽  
Egg Protein ◽  
Binding Data ◽  
Number Of Binding Sites ◽  
Lower Temperature ◽  
Scatchard Plots ◽  
Statistical Effects

AbstractThe binding of mercury (II) ion has been studied with egg protein at different pH values and temperatures by the polarographic technique. The binding data were found to be pH and temperature dependent. The intrinsic association constants (k) and the number of binding sites (n) were calculated from Scatchard plots and found tobe at the maximum at lower pH and at lower temperatures. The free energy change (ΔG°) of the combining sites were least at the higher pH and highest at the low pH; therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with mercury (II) ions. Statistical effects seem to be more significant at lower mercury (II) ion concentrations, while at higher concentrations electrostatic effects and heterogeneity of sites are more significant.

Spectrometric, Thermodynamic, pH Metric and Viscometric Studies on the Binding of TEALS as Surfactant with Albumin as Biopolymer

2020 ◽  
Vol 10 (1) ◽  
pp. 47-64
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma
Keyword(s):  
Binding Sites ◽  
Equilibrium Dialysis ◽  
Protein Molecule ◽  
Structure Characterization ◽  
Binding Interaction ◽  
Practical Applications ◽  
Egg Protein ◽  
Binding Data ◽  
Number Of Binding Sites ◽  
Lower Temperature

Background:: Since the interactions of small anions with protein are very important in their transportation and distribution processes in biological systems, it is helpful to study these interactions to understand the nature of the transportation and distribution processes. Therefore, it is aimed to study the interaction of albumin with surfactant molecule by different physical methods. Objective:: Present work attempts to work on assessing the structure, characterization of the surfactants as TEALS (tri-ethanalamine lauryl sulphate) binding sites, with albumin involved in various process of living being are discussed. Method:: The binding of surfactant TEALS to egg protein has been studied at different pH values and temperatures by spectrophotometric and equilibrium dialysis methods. The binding data were found to be pH and temperature dependent. The binding data studied by the absorbance method, were found approximately identical with those obtained from the equilibrium dialysis method. Results:: The association constants and the number of binding sites were calculated from Scatchard plots and found to be at maximum at lower pH and at lower temperature. The free energy of the combining sites was lowest at higher pH and highest at low pH. Therefore, a lower temperature and a lower pH offered more sites in the protein molecule for interaction with surfactant. The ΔG (free energies of aggregation) associated with the binding interaction of the surfactants and protein were calculated. The negative values of the ΔG confirm the feasibility of interaction between the surfactant and protein. All the observations recorded in this paper indicate that the TEALS has a good affinity of binding with egg protein and the number of binding sites is dependent on various physical and chemical factors. Conclusion:: On the basis of the results of the experiments which were conducted to examine the interaction between anionic surfactant and protein by measuring the various parameters of the solutions, it is concluded that the interaction of surfactant and protein gives an idea of fundamental understanding of the structure of surfactant-protein complex and their practical applications in every field.

The Thermodynamic and pH Metric Binding Studies of Cu+2 Ions with Egg Protein by Spectrometric and Diffusion Current Techniques

2020 ◽  
Vol 234 (3) ◽  
pp. 441-460 ◽  
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma
Keyword(s):  
Metal Ion ◽  
Copper Ions ◽  
Protein Molecule ◽  
Living System ◽  
Diffusion Current ◽  
Binding Studies ◽  
Spectrophotometric Methods ◽  
Egg Protein ◽  
Physico Chemical ◽  
Lower Temperature

AbstractTransition metals have unique efficacy in catalyzing various industrial reactions and also in living system, the redox reaction and redox changes in the metal ions catalyzed valence changes in the substrate molecule. The survey of the existing literature revealed that the binding of Molybdenum, Vanadium, Zinc, Cadmium, Copper, Nickel and Cobalt with the protein is well known but no binding studies of copper metal with egg protein are reported. With a view to extend the existing knowledge of ecological nature of metal-protein system, it was thought of interest to investigate the properties of metal-protein mixture. Investigations on the aspects of these binding problems were planned and their bindings constants have been determined using suitable physico-chemical methods. The pH metric, diffusion current measurements, spectrophotometric methods have been used on the binding of copper ions with albumin. The effect of physico-chemical factors on interaction between divalent metal ion i.e. copper with albumin has been discussed. On the basis of observed results, it is found that the binding data were dependent on pH and temperature. From scatchard plots, the intrinsic association constants (k) and the number of binding sites (n) were calculated and found high at lower pH and temperatures. Therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with copper (II) ions. The enthalpy (ΔH), entropy (ΔS) changes, free energy change (ΔG°) have been calculated.

Abnormal Platelet Serotonin Uptake and Binding Sites in Myeloproliferative Disorders

1984 ◽  
Vol 51 (03) ◽  
pp. 349-353 ◽  
Author(s):  
C Caranobe ◽  
P Sié ◽  
F Fernandez ◽  
J Pris ◽  
S Moatti ◽  
...  
Keyword(s):  
Binding Sites ◽  
High Capacity ◽  
Specific Inhibitor ◽  
Myeloproliferative Disorders ◽  
Normal Subjects ◽  
Binding Data ◽  
Full Explanation ◽  
Number Of Binding Sites ◽  
5 Ht Uptake ◽  
Kinetics Of

SummaryA simultaneous investigation of the kinetics of serotonin (5 HT) uptake and of binding sites was carried out in the platelets of normal subjects and of 10 patients affected with various types of myeloproliferative disorders (MD). The 5 HT uptake was analysed according to the Lineweaver-Burk and the Eadie-Hofstee methods. With the two methods, the patient’s platelets exhibited a dramatic reduction of the Vi max and of the Km; in some patients the Eadie-Hofstee analysis revealed that a passive diffusion phenomenon is superimposed on the active 5 HT uptake at least for the higher concentration used. The binding data were analysed with the Scatchard method. Two classes of binding sites (high affinity - low capacity, low affinity - high capacity) were found in normal subjects and patients. Pharmacological studies with imipramine, a specific inhibitor of 5 HT uptake, suggested that both the sites are involved in 5 HT uptake. The number of both binding sites was significantly decreased in patient’s platelets while the affinity constants of these binding sites were not significantly reduced in comparison with those of the control subjects. No correlations were found between Vi max, Km and the number of binding sites. These results suggest that a reduction in the number of platelet membrane acceptors for 5 HT commonly occurs in myeloproliferative disorders but does not provide a full explanation of the uptake defect.

The Binding and Viscometric Studies of Ni+2, Co+2 and Mn+2 Ions with Protein by Spectrometric and pH Metric Techniques

2019 ◽  
Vol 9 (2) ◽  
pp. 151-162
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Protein Molecule ◽  
Vital Role ◽  
Sufficient Evidence ◽  
Structural Requirement ◽  
Nickel Ions ◽  
Cobalt Ions ◽  
Lower Temperature ◽  
Specific Oxidation

Background: The metal ions play a vital role in a large number of widely differing biological processes. Some of these processes are quite specific in their metal ion requirements. In that only certain metal ions, in specific oxidation states, can full fill the necessary catalytic or structural requirement, while other processes are much less specific. Objective: In this paper we report the binding of Mn (II), Ni (II) and Co (II) with albumin are reported employing spectrophotometric and pH metric method. In order to distinguish between ionic and colloidal linking, the binding of metal by using pH metric and viscometric methods and the result are discussed in terms of electrovalent and coordinate bonding. Methods: The binding of Ni+2, Co+2 and Mn+2 ions have been studied with egg protein at different pH values and temperatures by the spectrometric technique. Results: The binding data were found to be pH and temperature dependent. The intrinsic association constants (k) and the number of binding sites (n) were calculated from Scatchard plots and found to be at the maximum at lower pH and at lower temperatures. Therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with these metal ions. Statistical effects seem to be more significant at lower Ni+2, Co+2 and Mn+2 ions concentrations, while at higher concentrations electrostatic effects and heterogeneity of sites are more significant. Conclusion: The pH metric as well as viscometric data provided sufficient evidence about the linking of cobalt, nickel and manganese ions with the nitrogen groups of albumin. From the nature and height of curves in the three cases it may be concluded that nickel ions bound strongly while the cobalt ions bound weakly.

Adrenergic receptors on cerebral microvessels: pericyte contribution

1989 ◽  
Vol 256 (1) ◽  
pp. R224-R230 ◽  
Author(s):  
R. M. Elfont ◽  
P. R. Sundaresan ◽  
C. D. Sladek
Keyword(s):  
Endothelial Cells ◽  
Binding Sites ◽  
Adrenergic Receptors ◽  
Radioligand Binding ◽  
Dissociation Constants ◽  
Specific Binding ◽  
Binding Studies ◽  
Cerebral Microvessels ◽  
Beta Adrenoceptor ◽  
Number Of Binding Sites

R224-R230, 1989.--[125I]iodocyanopindolol ([125I]ICYP) and [3H]rauwolscine were used to quantitate, respectively, the beta- and alpha 2-adrenergic receptors in freshly isolated bovine cerebral microvessels and in pericyte cultures derived from these microvessels. Morphological and immunocytochemical criteria distinguished the pericytes from endothelial cells. Competitive binding studies established the specificity of the radioligand binding. The maximal number of binding sites (Bmax) for [125I]ICYP in the pericytes constituted only 8% of that in the microvessels (3.5 +/- 1.3 vs. 44.4 +/- 6.6 fmol/mg protein). In contrast, the Bmax for [3H]rauwolscine in the pericytes was 50% of that in the microvessels (55.4 +/- 11.8 vs. 111.1 +/- 9.5 fmol/mg protein). The dissociation constants for both [125I]ICYP and [3H]rauwolscine were similar in the two preparations. No alpha 1-adrenergic receptors, as defined by the specific binding of [3H]prazosin, were identified either in the pericytes or microvessels. Overall, our results suggest that pericytes contribute minimally to the total beta-adrenoceptor number of cerebral microvessels, and thus the beta-adrenoceptors must be located predominantly on endothelial cells. However, the contribution of pericytes to the total alpha 2-adrenoceptor number of the microvessels may be substantial.

scholarly journals Common Receptor for Bacillus thuringiensis Toxins Cry1Ac, Cry1Fa, and Cry1Ja in Helicoverpa armigera, Helicoverpa zea, and Spodoptera exigua

2005 ◽  
Vol 71 (9) ◽  
pp. 5627-5629 ◽  
Author(s):  
Carmen Sara Hernández ◽  
Juan Ferré
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Armigera ◽  
Helicoverpa Zea ◽  
Spodoptera Exigua ◽  
Cross Resistance ◽  
Binding Studies ◽  
Lepidopteran Species ◽  
Common Receptor ◽  
Binding Data ◽  
Helicoverpa Armígera

ABSTRACT Binding studies using 125I-Cry1Ac and biotinylated Cry1Fa toxins indicate the occurrence of a common receptor for Cry1Ac, Cry1Fa, and Cry1Ja in Helicoverpa armigera, Helicoverpa zea, and Spodoptera exigua. Our results, along with previous binding data and the observed cases of cross-resistance, suggest that this pattern seems to be widespread among lepidopteran species.

THE PLATELET “REBOUND-PHENOMENON” DURING PROLONGED, CONTINUOUS PGI2 INFUSION OCCURS AT THE RECEPTOR LEVEL

1987 ◽  
Author(s):  
G Steurer ◽  
H Sinzinger ◽  
P Fitscha
Keyword(s):  
Binding Sites ◽  
Venous Blood ◽  
Intermittent Infusion ◽  
Receptor Level ◽  
Binding Data ◽  
Post Infusion ◽  
Number Of Binding Sites ◽  
Rebound Phenomenon ◽  
Infusion Regimen

During earlier attempts in optimizing the therapeutic regimen with PGI2 we were able to discover an “ intra- and post-infusion platelet rebound” being characterized by an activated platelet function and a diminished responsiveness of platelets to the action of PGI2 in-vitro.In order to verify this phenomenon at the receptor level we infused continuously 6 patients suffering from peripheral vascular disease (PVD) with PGI2 at a rate of 5 ng/kg/min for 5 days. Anticoagulated venous blood has been drawn at different intervals. Saturation binding experiments on platelet membrane fraction have been performed using [3H]iloprost, a stable PGI2 analoque. Analysis of the binding data according to Scatchard demonstrated a decrease of receptor affinity with an increased number of binding sites.It is concluded, that intrainfusion rebound occurs at the receptor level, whereas the postinfusion rebound does not. This is a further piece of evidence that an intermittent infusion regimen is preferable.

Temperature-dependent binding of cyclosporine to an erythrocyte protein.

1987 ◽  
Vol 33 (4) ◽  
pp. 481-485 ◽  
Author(s):  
R P Agarwal ◽  
G A Threatte ◽  
R A McPherson
Keyword(s):  
Binding Constant ◽  
Binding Capacity ◽  
Equilibrium Dialysis ◽  
Temperature Dependent ◽  
Fixed Amount ◽  
Competitive Binding Assay ◽  
Plot Analysis ◽  
Binding Data ◽  
Saturation Capacity ◽  
Increasing Temperature

Abstract In this competitive binding assay to measure endogenous binding capacity for cyclosporine (CsA) in erythrocyte lysates, a fixed amount of [3H]CsA plus various concentrations of unlabeled CsA is incubated with aliquots of a test hemolysate. Free CsA is then adsorbed onto charcoal and removed by centrifugation; CsA complexed with a cyclosporine-binding protein (CsBP) remains in the supernate. We confirmed the validity of this charcoal-separation mode of binding analysis by comparison with equilibrium dialysis. Scatchard plot analysis of the results at 4 degrees C yielded a straight line with slope corresponding to a binding constant of 1.9 X 10(7) L/mol and a saturation capacity of approximately 4 mumol per liter of packed erythrocytes. Similar analysis of binding data at 24 degrees C and 37 degrees C showed that the binding constant decreased with increasing temperature, but the saturation capacity did not change. CsBP was not membrane bound but appeared to be freely distributed within erythrocytes. 125I-labeled CsA did not complex with the erythrocyte CsBP. Several antibiotics and other drugs did not inhibit binding between CsA and CsBP. These findings may explain the temperature-dependent uptake of CsA by erythrocytes in whole blood and suggest that measurement of CsBP in erythrocytes or lymphocytes may help predict therapeutic response or toxicity after administration of CsA.

The Binding Of 125I-Von Willebrand Factor To Human Platelets In The Presence Of Ristocetin

1981 ◽  
Author(s):  
P Silber ◽  
T H Finlay
Keyword(s):  
Von Willebrand Factor ◽  
Binding Sites ◽  
Binding Constant ◽  
Specific Binding ◽  
Human Platelets ◽  
Scatchard Analysis ◽  
Binding Data ◽  
Number Of Binding Sites ◽  
Von Willebrand ◽  
Willebrand Factor

The effect of ristocetin on the binding of 125I-porcine von Willebrand factor to human platelets was studied. Previously, we had shown that 125I-porcine von Willebrand factor binds to human platelets in the absence of ristocetin. The present work demonstrates that binding is stimulated by ristocetin and this stimulation is maximal at a ristocetin concentration of 2 mg/ml. At a ristocetin concentration of 0.5 mg/ml, Scatchard analysis indicates a binding constant of 5.18 × 10-9M and the presence of 105,000 binding sites. This compares with our previous finding, in the absence of ristocetin, of a binding constant of 2.92 × 10-7M and 4760 binding sites. These binding data assume the porcine von Willebrand factor to be a tetramer with a molecular weight of 9 × 105. This study indicates that ristocetin causes tighter binding and increases the number of binding sites on human platelets for porcine von Willebrand factor. Unlabelled porcine von Willebrand factor competitively inhibits the specific binding of the labelled protein and gives a binding constant of 0.17 × 10-9M. Similar results were obtained using human von Willebrand factor.

THERMOFIELD ANALYSIS OF MAGNON SQUEEZING STATE IN THE FERROMAGNET

2008 ◽  
Vol 22 (20) ◽  
pp. 1931-1939
Author(s):  
QINFENG XU ◽  
ZE CHENG ◽  
YUNXIA PING
Keyword(s):  
Thermal Field ◽  
Zero Point ◽  
Vacuum State ◽  
Field Approximation ◽  
Spin Component ◽  
Zero Temperature ◽  
Temperature Dependent ◽  
Consistent Field ◽  
Self Consistent Field ◽  
Lower Temperature

In this paper, we introduce the self-consistent field approximation to treat with the nonlinear interaction among spin waves. Then temperature-dependent Bogoliubov transformation is introduced to generate a new representation which engenders the transition from the zero temperature to the finite temperature. At last, temperature-dependent quantum fluctuation properties of magnons are discussed in the thermal field. At lower temperature, we find that the fluctuation of spin-component at some given time regions can be below the zero-point fluctuation level of the vacuum state and exhibit a periodical squeezing behavior. In particular, these squeezed effects vanish with the increasing of temperature. These squeezing effects differ from the previous studies.

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