HETEROGENEITY OF INSULIN: I. ISOLATION OF A CHROMATOGRAPHICALLY PURIFIED, HIGH-POTENCY INSULIN AND SOME OF ITS PROPERTIES

1966 ◽  
Vol 44 (8) ◽  
pp. 1171-1181 ◽  
Author(s):  
W. W. Dillon ◽  
R. G. Romans
Keyword(s):  
Biological Activity ◽  
Gel Electrophoresis ◽  
Sodium Phosphate ◽  
Chemical Degradation ◽  
Minor Components ◽  
Slight Improvement ◽  
High Potency ◽  
Sodium Phosphate Buffer ◽  
A Value ◽  
Main Component

A slight improvement in the chromatography of insulin on Amberlite IRC-50 resin in 7 M urea −0.13 M sodium phosphate buffer, pH 6.05, at 3 °C revealed the presence of at least four components.The major component was found to have a potency greater than that of any other purified insulin hitherto reported and substantiated. The biological activity of the minor components varied from a value close to that of the starting insulin down to very low or negligible values, indicating a loss of biological activity with increasing chemical degradation. The potency studies were quantitative.Starch-gel electrophoresis showed that the main component was not completely homogeneous, traces of other components being present.A highly fluorescent, colored material was separated from among the minor components and may be of interest in relation to allergy produced by some insulins.The separation reported here is discussed in relation to other fractionation procedures.

A STUDY OF THE HETEROGENEITY OF PARATHYROID HORMONE PREPARATIONS

1969 ◽  
Vol 44 (2) ◽  
pp. 195-202
Author(s):  
D. J. LEA ◽  
J. M. ZANELLI
Keyword(s):  
Biological Activity ◽  
Parathyroid Hormone ◽  
Active Site ◽  
Gel Electrophoresis ◽  
Gel Filtration ◽  
Parathyroid Glands ◽  
Biologically Active ◽  
Antigenic Determinants ◽  
High Potency

SUMMARY Bovine parathyroid glands, stored in several ways, have been extracted by published methods using urea and HCl, or phenol, and recent modifications of the latter method utilizing mercaptoethanol. The extracts were purified by gel filtration. Parathyroid hormone of high potency has been obtained only from rapidly frozen glands by the method using phenol and mercaptoethanol. Purified hormone preparations were extremely heterogeneous, were indistinguishable from material of much lower potency by gel electrophoresis, and shared common antigenic determinants with components of fractions having insignificant biological activity. It is possible that parathyroid hormone which has been modified irreversibly at the biologically active site is commonly present in gland extracts.

scholarly journals Preparation of the lactate oxidase apoenzyme and studies on the binding of flavin mononucleotide to the apoenzyme

1975 ◽  
Vol 145 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Y S Choong ◽  
M G Shepherd ◽  
P A Sullivan
Keyword(s):  
Mycobacterium Smegmatis ◽  
Gel Electrophoresis ◽  
Sodium Phosphate ◽  
Specific Activity ◽  
Native Enzyme ◽  
Flavin Mononucleotide ◽  
Lactate Oxidase ◽  
Extinction Coefficients ◽  
Sodium Phosphate Buffer ◽  
Rapid Binding

1. Lactate oxidase from Mycobacterium smegmatis is completely resolved into free flavin and apoenzyme by treatment with acid (NH4)2SO4. 2. Reconstitution involves rapid binding of FMN, but the recovery of enzyme activity was slower and appeared to be biphasic. 3. The preparation of the holoenzyme obtained differs from the native enzyme in specific activity, extinction coefficients and mobility on disc-gel electrophoresis. 4. Dialysis of this reconstituted enzyme in 0.1 M-sodium phosphate buffer, pH 7.0, at 0 degrees C for 1 week yields a preparation which closely resembles the native enzyme.

Fluorocitrate Neural Dystrophy of the Guinea Pig Cochlea

1975 ◽  
Vol 33 ◽  
pp. 368-369
Author(s):  
G.J. Spector ◽  
C.D. Carr ◽  
I. Kaufman Arenberg ◽  
R.H. Maisel
Keyword(s):  
Hearing Loss ◽  
Hair Cells ◽  
Sodium Phosphate ◽  
Sensory Cells ◽  
Barium Salt ◽  
Perfusion Medium ◽  
Cochlear Hair Cells ◽  
Neural Degeneration ◽  
Sodium Phosphate Buffer ◽  
Cochlear Neurons

All studies on primary neural degeneration in the cochlea have evaluated the end stages of degeneration or the indiscriminate destruction of both sensory cells and cochlear neurons. We have developed a model which selectively simulates the dystrophic changes denoting cochlear neural degeneration while sparing the cochlear hair cells. Such a model can be used to define more precisely the mechanism of presbycusis or the hearing loss in aging man.Twenty-two pigmented guinea pigs (200-250 gm) were perfused by the perilymphatic route as live preparations using fluorocitrate in various concentrations (15-250 ug/cc) and at different incubation times (5-150 minutes). The barium salt of DL fluorocitrate, (C6H4O7F)2Ba3, was reacted with 1.0N sulfuric acid to precipitate the barium as a sulfate. The perfusion medium was prepared, just prior to use, as follows: sodium phosphate buffer 0.2M, pH 7.4 = 9cc; fluorocitrate = 15-200 mg/cc; and sucrose = 0.2M.

scholarly journals Evaluation of equilibrium constants for the interaction of lactate dehydrogenase isoenzymes with reduced nicotinamide-adenine dinucleotide by affinity chromatography

1975 ◽  
Vol 151 (3) ◽  
pp. 631-636 ◽  
Author(s):  
R I Brinkworth ◽  
C J Masters ◽  
D J Winzor
Keyword(s):  
Lactate Dehydrogenase ◽  
Affinity Chromatography ◽  
Equilibrium Constants ◽  
Mouse Tissue ◽  
Rabbit Muscle ◽  
Muscle Lactate ◽  
Sodium Phosphate Buffer ◽  
A Value ◽  
Series Of Experiments ◽  
Reduced Nicotinamide Adenine Dinucleotide

Rabbit muscle lactate dehydrogenase was subjected to frontal affinity chromatography on Sepharose-oxamate in the presence of various concentrations of NADH and sodium phosphate buffer (0.05 M, pH 6.8) containing 0.5 M-NaCl. Quantitative interpretation of the results yields an intrinsic association constant of 9.0 × 104M−1 for the interaction of enzyme with NADH at 5°C, a value that is confirmed by equilibrium-binding measurements. In a second series of experiments, zonal affinity chromatography of a mouse tissue extract under the same conditions was used to evaluate assoication constants of the order 2 × 105M−1, 3 × 105M−1, 4 × 105M−1, 7 × 105M−1 and 2 × 106M−1 for the interaction of NADH with the M4, M3H, M2H2, MH3 and H4 isoenzymes respectively of lactate dehydrogenase.

Effects of sodium phosphate buffer on horseradish peroxidase thermal stability

2008 ◽  
Vol 93 (2) ◽  
pp. 569-574 ◽  
Author(s):  
L. Haifeng ◽  
L. Yuwen ◽  
C. Xiaomin ◽  
W. Zhiyong ◽  
W. Cunxin
Keyword(s):  
Thermal Stability ◽  
Horseradish Peroxidase ◽  
Phosphate Buffer ◽  
Sodium Phosphate ◽  
Sodium Phosphate Buffer

INACTIVATION AND DEGRADATION OF PORCINE CALCITONIN BY RAT LIVER, AND RELATIVE STABILITY OF SALMON CALCITONIN

1970 ◽  
Vol 48 (2) ◽  
pp. 181-188 ◽  
Author(s):  
M. de LUISE ◽  
T. J. MARTIN ◽  
R. A. MELICK
Keyword(s):  
Biological Activity ◽  
Rat Liver ◽  
Salmon Calcitonin ◽  
Trichloroacetic Acid ◽  
Maximal Activity ◽  
Active Principle ◽  
Rat Tissues ◽  
Prolonged Action ◽  
High Potency ◽  
Dose Dependent

SUMMARY Slices and homogenates of a number of rat tissues inactivated porcine calcitonin labelled with 125I; the most active tissue was the liver. Maximal activity was found in rat liver supernatant. The reaction was pH- and dose-dependent, the active principle was non-diffusible, inhibited by p-chloromercuribenzoate and EDTA, and destroyed by heat. Biological activity of calcitonin was lost parallel with the breakdown of the labelled calcitonin (as measured by loss of trichloroacetic acid precipitability). Salmon ultimobranchial calcitonin was much less susceptible to inactivation by rat liver supernatant than the porcine hormone, which may explain the high potency and prolonged action of the salmon hormone in the rat.

Study on the Synthesis of Carboxymethylpachyman in the Aqueous-Ethanol Medium with the Assistance of Ultrasonics

2011 ◽  
Vol 236-238 ◽  
pp. 2810-2814
Author(s):  
Yong Jiang Wang ◽  
Xue Qian Wu ◽  
Shi Wang Liu ◽  
Yuan Feng Wu ◽  
Yan Ping Zhang
Keyword(s):  
Biological Activity ◽  
Aqueous Ethanol ◽  
Reaction Medium ◽  
Volume Ratio ◽  
Value Added ◽  
Poria Cocos ◽  
A Value ◽  
Ethanol Medium ◽  
Favorable Conditions ◽  
Carboxymethyl Pachyman

Water-insoluble β - ( 1 - 3 ) – D - glucan isolated from the sclerotium of Poria cocos hardly exhibits biological activity. Therefore, it is advantageous to produce a value-added product from Poria cocos. We extracted the β - ( 1 - 3 ) – D - glucan from the sclerotium of Poria cocos and synthesized a carboxymethylated derivative, carboxymethyl-pachyman (CMP). The influences on the degrees of substitution ( DS ) of CMP, for example, volume ratio of ethanol to water, [NaOH]/[MCA] ratio, reaction temperature and reaction time have been examined, respectively. The most favorable conditions for pachyman carboxymethylation are obtained with a [NaOH]/[MCA] ratio of 1.5, at 45°C for 60 minutes with a reaction medium consisting of a ethanol/water 80:20 (v/v) mixture.

Recovery of milk fat globule membrane (MFGM) from buttermilk: effect of Ca-binding salts

2019 ◽  
Vol 86 (3) ◽  
pp. 374-376 ◽  
Author(s):  
Vitaly L. Spitsberg ◽  
Liza Ivanov ◽  
Vladimir Shritz
Keyword(s):  
Phosphate Buffer ◽  
Milk Fat ◽  
Sodium Phosphate ◽  
Milk Fat Globule Membrane ◽  
Peripheral Protein ◽  
Sodium Phosphate Buffer ◽  
Milk Fat Globule ◽  
Fat Globule ◽  
First Time ◽  
Phosphate Groups

AbstractIn this Research Communication we present a study of the effect of Ca-binding salts on the recovery of milk fat globule membrane (MFGM) from buttermilk. Sodium phosphate buffer was used for the purpose of MFGM recovery from buttermilk for the first time and we showed that 0.1 M buffer at pH 7.2 was the most effective for the recovery of MFGM. The fact of high efficacy of sodium phosphate buffer in recovery of MFGM from buttermilk allowed us to suggest that MFGM in buttermilk is present in association with casein through Ca- bridges formed between phospholipids of MFGM and phosphate groups of casein, primarily with k-casein as the peripheral protein of casein micelles.

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