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.

Seasonal changes in plasma androgens, glucocorticoids and glucocorticoid-binding proteins in the marsupial sugar glider Petaurus breviceps

1992 ◽  
Vol 132 (1) ◽  
pp. 21-31 ◽  
Author(s):  
A. J. Bradley ◽  
D. M. Stoddart
Keyword(s):  
Plasma Concentration ◽  
Breeding Season ◽  
Binding Constant ◽  
Binding Capacity ◽  
Equilibrium Dialysis ◽  
Plasma Testosterone ◽  
High Affinity ◽  
Sugar Glider ◽  
Free Cortisol ◽  
Petaurus Breviceps

ABSTRACT An investigation spanning two breeding seasons was carried out to examine endocrine changes associated with reproduction in a wild population of the marsupial sugar glider Petaurus breviceps, a small arboreal gliding possum. Using techniques of equilibrium dialysis and polyacrylamide gel electrophoresis at steady-state conditions, a high-affinity, low-capacity glucocorticoid-binding protein was demonstrated in the plasma of Petaurus breviceps. Equilibrium dialysis at 36 °C using cortisol gave a high-affinity binding constant of 95 ± 5·2 litres/μmol for a presumed corticosteroid-binding globulin (CBG) while the binding constant for the cortisol-albumin interaction was 3·5 ± 0·4 litres/mmol. There was no difference between the sexes in the affinity of binding of cortisol to CBG; however, the cortisol-binding capacity underwent seasonal variation in both sexes. Progesterone was bound strongly to the presumed CBG while neither oestradiol nor aldosterone appeared to be bound with high affinity to P. breviceps plasma. In the males, peaks in the plasma concentration of testosterone coincided with the July–September breeding season in both years. A significant inverse relationship was shown to exist between the plasma testosterone concentration and the CBG-binding capacity. In both sexes an increase occurred in the plasma concentration of free cortisol during the first breeding season, a pattern which was not repeated in the subsequent breeding season, possibly due to a lower population density in that year. Journal of Endocrinology (1992) 132, 21–31

Mechanism of depression in cardiac sarcolemmal Na+-K+-ATPase by hypochlorous acid

1998 ◽  
Vol 275 (3) ◽  
pp. C826-C831 ◽  
Author(s):  
Kiminori Kato ◽  
Qiming Shao ◽  
Vijayan Elimban ◽  
Anton Lukas ◽  
Naranjan S. Dhalla
Keyword(s):  
Atpase Activity ◽  
Hypochlorous Acid ◽  
Binding Capacity ◽  
Ischemia Reperfusion ◽  
Maximal Velocity ◽  
Dependent Manner ◽  
Ouabain Binding ◽  
Plot Analysis ◽  
Binding Data ◽  
Atpase Subunits

Oxidative stress during pathological conditions such as ischemia-reperfusion is known to promote the formation of hypochlorous acid (HOCl) in the heart and to result in depression of cardiac sarcolemmal (SL) Na+-K+-ATPase activity. In this study, we examined the direct effects of HOCl on SL Na+-K+-ATPase from porcine heart. HOCl decreased SL Na+-K+-ATPase activity in a concentration- and time-dependent manner. Characterization of Na+-K+-ATPase activity in the presence of different concentrations of MgATP revealed a decrease in the maximal velocity ( V max) value, without a change in affinity for MgATP on treatment of SL membranes with 0.1 mM HOCl. The V max value of Na+-K+-ATPase, when determined in the presence of different concentrations of Na+, was also decreased, but affinity for Na+ was increased when treated with HOCl. Formation of acylphosphate by SL Na+-K+-ATPase was not affected by HOCl. Scatchard plot analysis of [3H]ouabain binding data indicated no significant change in the affinity or maximum binding capacity value for ouabain binding following treatment of SL membranes with HOCl. Western blot analysis of Na+-K+-ATPase subunits in HOCl-treated SL membranes showed a decrease (34 ± 9% of control) in the β1-subunit without any change in the α1- or α2-subunits. These data suggest that the HOCl-induced decrease in SL Na+-K+-ATPase activity may be due to a depression in the β1-subunit of the enzyme.

scholarly journals Monitoring the temperature-dependent elastic and anelastic properties in isotropic polycrystalline ice using resonant ultrasound spectroscopy

2016 ◽  
Vol 10 (6) ◽  
pp. 2821-2829 ◽  
Author(s):  
Matthew J. Vaughan ◽  
Kasper van Wijk ◽  
David J. Prior ◽  
M. Hamish Bowman
Keyword(s):  
Sea Ice ◽  
Ice Cores ◽  
Compressional Wave ◽  
Temperature Dependent ◽  
Resonant Ultrasound Spectroscopy ◽  
Polycrystalline Ice ◽  
Passive Seismic ◽  
Resonant Ultrasound ◽  
Increasing Temperature ◽  
Quality Factor Q

Abstract. The elastic and anelastic properties of ice are of interest in the study of the dynamics of sea ice, glaciers, and ice sheets. Resonant ultrasound spectroscopy allows quantitative estimates of these properties and aids calibration of active and passive seismic data gathered in the field. The elastic properties and anelastic quality factor Q in laboratory-manufactured polycrystalline isotropic ice cores decrease (reversibly) with increasing temperature, but compressional-wave speed and attenuation prove most sensitive to temperature, indicative of pre-melting of the ice. This method of resonant ultrasound spectroscopy can be deployed in the field, for those situations where shipping samples is difficult (e.g. remote locations), or where the properties of ice change rapidly after extraction (e.g. in the case of sea ice).

Temperature Dependent Raman Scattering in CsTiOAsO4 Single Crystal

1995 ◽  
Vol 398 ◽  
Author(s):  
A.R. Guo ◽  
C.-S. Tu ◽  
Ruiwu Tao ◽  
R.S. Katiyar ◽  
Ruyan Guo ◽  
...  
Keyword(s):  
Soft Mode ◽  
Low Frequency ◽  
High Mobility ◽  
Vibrational Modes ◽  
Frequency Range ◽  
Temperature Dependent ◽  
Higher Symmetry ◽  
Phonon Spectra ◽  
Symmetry Structure ◽  
Increasing Temperature

ABSTRACTThe longitudinal (LO) and transverse (TO) A1 vibrational modes have been measured between 30-1200 cm−1 as a function of temperature (30–1240 K) for CsTiOAsO4 (CTA). The frequencies for all corresponding Raman components shifted to lower frequencies on increasing the temperature, however, there is no typical soft-mode like behavior observed in the measured frequency range. The relative intensities of the low frequency bands increase dramatically with increasing temperature due to high mobility of Cs+ ion. A higher symmetry structure taking place above 940K has been confirmed by changes in the phonon spectra.

Morphological basis for the complex melting behaviour of isotactic polystyrene

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Mahmoud Al-Hussein ◽  
Gert Strobl
Keyword(s):  
Morphological Changes ◽  
Melting Behaviour ◽  
Temperature Dependent ◽  
Molten Material ◽  
Scanning Calorimetry ◽  
Isotactic Polystyrene ◽  
X Ray ◽  
Long Period ◽  
X Ray Scattering ◽  
Increasing Temperature

AbstractTemperature-dependent small-angle X-ray scattering spectroscopy of isothermally cold crystallized isotactic polystyrene revealed considerable morphological reorganization during subsequent heating to the melt. Both the crystalline thickness and the long period increased continuously with increasing temperature before the samples finally melted. The temperature dependence of these changes correlated very well with the melting behaviour observed with differential scanning calorimetry. As the temperature increased during a heating scan, the initial lamellae that formed during isothermal crystallization showed only little reorganization until they started to melt. Then, the molten material recrystallized continuously into increasingly thicker lamellae at increasing temperature until they finally melted. As the crystallization temperature approached the final melting temperature of the recrystallized lamellae, the initial lamellae melted without further recrystallization and no morphological changes were seen in this case.

scholarly journals An approach based on diffusion to study ligand-macromolecule interaction.

2002 ◽  
Vol 49 (3) ◽  
pp. 703-707 ◽  
Author(s):  
Mohammad R Housaindokht ◽  
Mahmood Bahrololoom ◽  
Shirin Tarighatpoor ◽  
Ali A Mossavi-Movahedi
Keyword(s):  
Methyl Orange ◽  
Diffusion Process ◽  
Binding Constant ◽  
Phosphate Buffer ◽  
Binding Capacity ◽  
Free Ligand ◽  
Hill Equation ◽  
New Approach ◽  
Binding Isotherm ◽  
The Hill

A new approach has been developed to study binding of a ligand to a macromolecule based on the diffusion process. In terms of the Fick's first law, the concentration of free ligand in the presence of a protein can be determined by the measurement of those ligands which are diffused out. This method is applied to the study of binding of methyl-orange to lysozyme in phosphate buffer of pH 6.2, at 30 degrees C. The binding isotherm was determined initially, followed by application of the Hill equation to the data obtained, then binding constant and binding capacity were estimated.

Temperature-dependent survival and reproduction within populations of the ectoparasitic digenean Transversotrema patialense on the fish host

Parasitology ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 91-102 ◽  
Author(s):  
C. A. Mills
Keyword(s):  
Life Span ◽  
Egg Production ◽  
Fish Host ◽  
Adult Parasite ◽  
Optimum Temperature ◽  
Brachydanio Rerio ◽  
Temperature Dependent ◽  
Parasite Survival ◽  
Survival And Reproduction ◽  
Increasing Temperature

SUMMARYThe reproduction and survival of the ectoparasitic digenean Transversotrema patialense on the fish host Brachydanio rerio are shown to be temperature-dependent. Survival is reduced by any deviation from an optimum temperature of approximately 23°C. With increasing temperature the rate of egg production per surviving fluke rises progressively faster to a higher peak up to 29°C but falls to zero by 35°C. The span of egg production varies closely with the life-span of the parasite at each temperature. The optimum temperature for the total number of eggs produced by each cohort of parasites is also 23°C. This number is a function of both adult parasite survival and the rate of egg output.

Temperature Dependent Behavior of the Canine Medial Collateral Ligament

1987 ◽  
Vol 109 (1) ◽  
pp. 68-71 ◽  
Author(s):  
Savio L.-Y. Woo ◽  
Thay Q. Lee ◽  
Mark A. Gomez ◽  
Shigeru Sato ◽  
Frederic P. Field
Keyword(s):  
Medial Collateral Ligament ◽  
Viscoelastic Properties ◽  
Cyclic Load ◽  
Tensile Load ◽  
Temperature Dependent ◽  
Collateral Ligament ◽  
Dependent Behavior ◽  
Proportional Relationship ◽  
C 32 ◽  
Increasing Temperature

The temperature dependent tensile behavior of ligament was investigated from 2°C to 37°C. Nondestructive cyclic tests were performed on ten canine femur-medial collateral ligament-tibia (FMT) complexes at sequential temperatures of 22°C, 22°C, 27°C, 32°C, 37°C, and again at 22°C. The samples were rested at zero load between tests for sufficient time periods to allow for full recovery from the ligament’s time and history dependent viscoelastic properties. Ten additional FMT complexes were sequentially tested in a similar fashion, but at temperatures of 22°C, 22°C, 2°C, 6°C, 14°C, and 22°C. All canine FMT complexes showed temperature dependent viscoelastic properties: the measured area of hysteresis decreased with increasing temperature; the cyclic load relaxation behavior plateaued to a higher value at lower temperatures; and the tensile load at a predetermined ligament substance strain level had an inversely proportional relationship with respect to temperature.

scholarly journals The influence of temperature on methane adsorption in coal: A review and statistical analysis

2019 ◽  
Vol 37 (9-10) ◽  
pp. 745-763 ◽  
Author(s):  
Zhijun Wang ◽  
Xiaojuan Wang ◽  
Weiqin Zuo ◽  
Xiaotong Ma ◽  
Ning Li
Keyword(s):  
Coalbed Methane ◽  
Methane Adsorption ◽  
Gas Content ◽  
Future Research ◽  
Temperature Dependent ◽  
Current State ◽  
Influence Of Temperature On ◽  
State Of Research ◽  
Increasing Temperature ◽  
The Relationship

The capacity of coal to adsorb methane is greatly affected by temperature and, in recent years, temperature-dependent adsorption has been studied by many researchers. Even so, comprehensive conclusions have not been reached and conflicting experimental results are common. This paper reviews the current state of research regarding the temperature-dependent adsorption of methane in coal and catalogs the conclusions from experiments conducted on that subject by 28 researchers, as published between 1995 and 2017. Probability theory and statistics are used to show that the conclusion generally accepted by most researchers is that the amount of methane adsorbed by coal decreases with increasing temperature. It is highly likely that the Langmuir volume decreases as the temperature rises, and it is also probable that the Langmuir pressure increases at higher temperatures. Equations are presented that express the relationships between methane adsorption, Langmuir volume, Langmuir pressure, and temperature. Future research should be directed toward determining the relationship between Langmuir pressure and temperature. The results of the study presented herein provide a theoretical basis for predicting the gas content in coal seams and improving the efficiency of coalbed methane development.

Environment and Herbicide Effects on Canada Thistle Ecotypes

Weed Science ◽  
1972 ◽  
Vol 20 (2) ◽  
pp. 163-167 ◽  
Author(s):  
James H. Hunter ◽  
Leon W. Smith
Keyword(s):  
Acetic Acid ◽  
Root Development ◽  
Leaf Damage ◽  
Cirsium Arvense ◽  
Temperature Dependent ◽  
Canada Thistle ◽  
Anisic Acid ◽  
Herbicide Effects ◽  
Increasing Temperature ◽  
Dichlorophenoxy Acetic Acid

Root sections of seven Canada thistle(Cirsium arvense(L.) Scop.) ecotypes were grown under 8, 12, 14, and 16-hr photoperiods at 16, 21, and 27 C. Flowering occurred in all ecotypes under a 16-hr photoperiod. At the 14-hr photoperiod five ecotypes flowered; flowering in three of them was temperature-dependent. Shoot and root development and plant height varied with ecotype. Both the root-to-shoot ratios and the number of shoot buds formed on the roots were inversely related to temperature and length of photoperiod. Herbicides tested for their effects on Canada thistle were 4-amino-3,5,6-trichloropicolinic acid (picloram), 3,6-dichloro-o-anisic acid (dicamba), and (2,4-dichlorophenoxy)acetic acid (2,4-D). Control of top growth increased with increasing temperature. Similarly, root control was maximum at 27 C, at which temperature there were few fleshy roots. Picloram, unlike 2,4-D and dicamba, caused little leaf damage but completely destroyed the root system.

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