scholarly journals A study of calf thymus histone fraction F2(b) by gel filtration

1970 ◽  
Vol 120 (1) ◽  
pp. 61-66 ◽  
Author(s):  
P. A. Edwards ◽  
K. V. Shooter
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Spherical Symmetry ◽  
Gel Filtration ◽  
Histone Fraction ◽  
Salting Out ◽  
Hydrodynamic Volume ◽  
Calf Thymus ◽  
Stokes Radius ◽  
The Individual

The gel-filtration behaviour of calf thymus histone fraction F2(b) was studied at three different salt concentrations (0.01m-, 0.10m- and 1.00m-sodium chloride) and two different pH ranges (pH3–4 and pH6.7–7.1). Other histone fractions [F1, F2(a) and F3] were also utilized to assist interpretation of the data. It was found that the Stokes radius of histone fraction F2(b) was not significantly changed when the salt concentration was increased, implying that the aggregation of the individual histone molecules (Edwards & Shooter, 1969) resulted in only relatively minor changes in the hydrodynamic volume. Aggregation would appear to be due to the salting out of hydrophobic regions giving rise, in the aggregate, to a compact core of hydrophobic groups from which protrude the remaining basic parts of the molecule. Repulsion between charged groups on the basic regions of individual histone molecules would give the aggregate approximately spherical symmetry, the diameter of the aggregate approximating to the length of a single histone molecule.

scholarly journals Properties of halophil nicotinamide–adenine dinucleotide phosphate-specific isocitrate dehydrogenase. True Michaelis constants, reaction mechanisms and molecular weights

1972 ◽  
Vol 130 (3) ◽  
pp. 645-662 ◽  
Author(s):  
D. M. Aitken ◽  
A. D. Brown
Keyword(s):  
Reaction Mechanism ◽  
Sodium Chloride ◽  
Potassium Chloride ◽  
Salt Concentration ◽  
Isocitrate Dehydrogenase ◽  
Reaction Mechanisms ◽  
Substrate Concentration ◽  
Gel Filtration ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Michaelis Constants

True values of Michaelis constants of the NADP+-specific isocitrate dehydrogenase from Halobacterium salinarium were not very different from those of the apparent constants reported by Aitken et al. (1970). The true constants were affected by salt in a similar manner to that of the apparent constants obtained with NADP+ at fixed concentrations of 1.0–0.2mm and threo-ds-(+)-isocitrate at fixed concentrations of 2.0–0.125mm. The response of apparent Vmax. to salt concentration was highly dependent on fixed substrate concentration in solutions of sodium chloride but much less so in solutions of potassium chloride. At several levels the results emphasize the difficulty of generalizing about the salt relations of a halophil enzyme without adequate attention to substrate concentration. The enzyme has at least two different reaction mechanisms depending on salt concentration. In its ‘physiological’ form (i.e. in 1.0m-potassium chloride), and also in 1.0m-sodium chloride, the reaction mechanism is ordered with NADP+ the first substrate added and NADPH the last product released. In 0.25m-sodium chloride, however, the mechanism is different and is probably non-sequential. In 4.0m-sodium chloride with low concentrations of either fixed substrate, there was evidence of a co-operative action of the variable substrate. The evidence suggests that salt participates in the reaction mechanism in two ways: one is the reversible addition to the enzyme in a manner analogous to that of a substrate; the other is dead-end complex-formation. The relative contributions of these two types of reaction determine whether salt activates or inhibits the enzyme. In addition, the inhibition caused by high concentrations of sodium chloride is more complex than the corresponding inhibition by potassium chloride. Gel-filtration experiments indicated that at very low salt concentrations the enzyme has an apparent molecular weight of about 70800. In ‘physiological’ concentrations of potassium chloride the enzyme appears to be a dimer (mol.wt. 122000–135000) and, in 1.0–4.0m-sodium chloride, it behaves as a trimer or tetramer (mol.wt. 224000–251000). A preliminary method of purifying the enzyme is described.

scholarly journals РОЗРОБКА СПОСОБІВ ОТРИМАННЯ І АНАЛІЗ ФЕРМЕНТНИХ ПРЕПАРАТІВ ПЕРОКСИДАЗ ТА КАТАЛАЗ ДЕЯКИХ ВИДІВ БАЗИДІОМІЦЕТІВ

2013 ◽  
Vol 3 (01) ◽  
pp. 113 ◽  
Author(s):  
O. V. Fedotov ◽  
T. E. Voloshko
Keyword(s):  
Freeze Drying ◽  
Enzyme Preparation ◽  
Gel Filtration ◽  
Science Research ◽  
Individual Characteristics ◽  
Salting Out ◽  
Enzyme Preparations ◽  
Agrocybe Cylindracea ◽  
Activity Of Enzymes ◽  
The Individual

<p>A method for obtaining of enzyme preparations of enzyme preparations (EP) of peroxidases and catalases fungal extracellular and inracellular origin from cultures of Basidiomycetes was developed. The strains <em>Flammulina velutipes</em> F-vv, <em>Agrocybe cylindracea</em> 167; <em>Fistulina hepatica</em> Fh-08 and <em>Pleurotus ostreatus</em> P-208 and P-01 were used as producers of oxidoreductases. Strains were grown on modified glucose-peptone media. Fractionation was carried out by salting out the enzymes with ammonium sulfate at 40-70% saturation of peroxidases and 80% of saturation - for catalase. These solutions protein fractions was further purified by dialysis and gel filtration on Molselekt granules G-50 and G-75. The enzyme solution was subjected to freeze-drying. The individual characteristics of the enzyme preparations were found.  The individual characteristics of the enzyme preparations are the activity of enzymes, the protein content and amino-acid composition of enzyme preparations. It was established that strain <em>F. velutipes</em> F-vv was an active producer of intracellular and strain of <em>A. cylindracea</em> 167 was an active producer of extracellular peroxidase. The strains of <em>P. ostreatus</em> P-01 and P-208 were the active producers of extracellular catalase, and the strains of F. hepatica Fh-08 were active producers of intracellular catalase. The developed methods for producing of enzymes catalase and peroxidase preparations of extra-and intracellular origin provided new antioxidant enzymes, which have their own properties and application prospects in various sectors of industry and science research.</p> <p><em>Key words: Basidiomycetes, peroxidases, catalases, enzyme preparation.</em></p>

TURBIDITY OF SUSPENSIONS AND MORPHOLOGY OF RED HALOPHILIC BACTERIA AS INFLUENCED BY SODIUM CHLORIDE CONCENTRATION

1960 ◽  
Vol 6 (5) ◽  
pp. 535-543 ◽  
Author(s):  
Dinah Abram ◽  
N. E. Gibbons
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Morphological Changes ◽  
Halophilic Bacteria ◽  
Chloride Concentration ◽  
Chloride Content ◽  
Wall Structure ◽  
Abrupt Decrease ◽  
High Sodium ◽  
Rigid Cell Wall

The optical densities of suspensions of cells of Halobacterium cutirubrum, H. halobium, or H. salinarium, grown in media containing 4.5 M sodium chloride, increase as the salt concentration of the suspending medium decreases, until a maximum is reached at about 2 M; below this concentration there is an abrupt decrease in optical density. The cells are rod shaped in 4.5 M salt and change, as the salt concentration decreases, through irregular transition forms to spheres; equal numbers of transition forms and spheres are present at the point of maximum turbidity, while spheres predominate at lower salt concentrations. Cells suspended in 3.0 M salt, although slightly swollen, are viable, but viability decreases rapidly with the more drastic changes in morphology at lower salt concentrations. Cells grown in the presence of iron are more resistant to morphological changes but follow the same sequence. Cells "fixed" with formaldehyde, at any point in the sequence, act as osmometers and do not rupture in distilled water although their volume increases 10–14 times. The results indicate that the red halophilic rods require a high sodium chloride content in their growth or suspending medium to maintain a rigid cell wall structure.

scholarly journals A method for the selective extraction of histone fractions f2(a)1 and f2(a)2 from calf thymus deoxyribonucleoprotein at pH7

1967 ◽  
Vol 105 (2) ◽  
pp. 611-614 ◽  
Author(s):  
E W Johns
Keyword(s):  
Acid Solution ◽  
Selective Extraction ◽  
New Method ◽  
Guanidinium Chloride ◽  
Histone Fraction ◽  
Acetone Precipitation ◽  
Calf Thymus

1. A new method has been developed for the specific extraction of histone fraction f2(a) from calf thymus deoxyribonucleoprotein at pH7 by using a mixture of ethanol and guanidinium chloride. 2. Fraction f2(a) has been separated into the subfractions f2(a)1 and f2(a)2 by acetone precipitation from acid solution, and at pH7. 3. Modifications of existing electrophoretic methods are described that enable these fractions to be more easily characterized.

scholarly journals Cytosol oestrogen receptor of lactating mammary gland. Effect of heparin on the aggregation of the receptor and interaction of the receptor with heparin-Sepharose

1978 ◽  
Vol 171 (1) ◽  
pp. 137-141 ◽  
Author(s):  
F Auricchio ◽  
A Rotondi ◽  
P Sampaolo ◽  
E Schiavone
Keyword(s):  
Mammary Gland ◽  
Oestrogen Receptor ◽  
High Speed ◽  
Gradient Centrifugation ◽  
Gel Filtration ◽  
Sedimentation Coefficient ◽  
Large Aggregate ◽  
Low Salt ◽  
Lactating Mammary Gland ◽  
Stokes Radius

1. An oestrogen receptor is present in low-salt cytosol of the mammary gland of lactating mice as a large aggregate; it is excluded from gel matrix when filtered on a Sephadex G-200 column and sediments at 7S in sucrose gradients. After incubation of cytosol with heparin, the receptor is dissociated. On a Sephadex G-200 column, it is included in the gel matrix and eluted as a protein with mol.wt. 260000 and a Stokes radius of 6.8nm; it sediments at 6S in sucrose gradients. 2. Dissociation of the mammary-gland cytosol oestrogen receptor seems to be the result of interaction of the oestrogen-receptor complex with heparin. This receptor interacts with heparin covalently bound to Sepharose, thereafter sedimenting at 6S. By using this interaction, the cytosol receptor was purified 200-fold compared with the homogenate, with a yield of 70%. 3. The cytosol receptor that was not incubated or was incubated with heparin was much smaller during sucrose-gradient centrifugation than during gel filtration. This discrepancy can be explained by pressure-induced dissociation during high-speed centrifugation. This possibility is supported by the decrease in the sedimentation coefficient of the receptor with increased duration of centrifugation.

scholarly journals Effect of Xanthan and Arabic Gums on Foaming Properties of Pumpkin (Cucurbita pepo) Seed Protein Isolate

2013 ◽  
Vol 3 (1) ◽  
pp. 87 ◽  
Author(s):  
Quirino Dawa ◽  
Yufei Hua ◽  
Moses Vernonxious Madalitso Chamba ◽  
Kingsley George Masamba ◽  
Caimeng Zhang
Keyword(s):  
Sodium Chloride ◽  
Salt Concentration ◽  
Seed Protein ◽  
Foam Stability ◽  
Chloride Concentration ◽  
Egg White ◽  
Protein Isolate ◽  
Foaming Properties ◽  
Ph Optimum ◽  
Pumpkin Seed

<p>Understanding how foaming properties of proteins are affected by factors such as pH, salt concentration and temperature is essential in predicting their performance and utilisation. In this study, the effects of pH and salt concentration were studied on the foaming properties of pumpkin seed protein isolate (PSPI) and PSPI- xanthan (XG)/Arabic (GA) gum blends. The foaming properties of the PSPI-GA/XG blends were also compared with egg white. Foam stability (FS) was significantly affected by pH with PSPI: GA (25:4) and PSPI: XG (25:1) having a significantly higher stability at pH 2 with the lowest foam stability at pH 4. Sodium chloride (0.2-1.0 M) did not significantly affect foaming properties although PSPI: GA (25:4) had the highest FC (89.33 ± 3.24%) and FS (76.83 ± 1.53 min) at 0.2 M sodium chloride concentration. The foaming capacity (FC) of PSPI: GA (25:4) blend (128.00 ± 0.91%) was significantly higher (<em>p </em><em>&lt; </em>0<em>.</em>05) than that of egg white (74.00 ± 1.33%) but its FS was significantly lower. It was further revealed that the FC of egg white (74.00 ± 1.33%) was comparable to the PSPI:XG (25:1) blend (74.00 ± 1.46%) but the FS for egg white (480.00 ± 2.67 min) was significantly higher (<em>p </em><em>&lt; </em>0<em>.</em>05) than the FS (116.21 ± 0.86 min) of PSPI:XG (25:1). The foaming properties of PSPI and PSPI-xanthan (XG)/Arabic (GA) blends were significantly affected by pH. Optimum foaming properties, PSPI:XG (25:1) and PSPI:GA (25:4) were observed at pH 2 and heat treatment temperature of 80 ºC.</p>

Impacts of dyebath auxiliaries on the reductive discoloration of Acid Orange 7 dye by high-carbon iron filings

2016 ◽  
Vol 74 (5) ◽  
pp. 1217-1226
Author(s):  
Raja Kumar ◽  
Alok Sinha
Keyword(s):  
Iron Surface ◽  
Bulk Solution ◽  
Acid Orange 7 ◽  
High Carbon ◽  
Iron Corrosion ◽  
Salting Out ◽  
Reaction Phase ◽  
Acid Orange ◽  
Carbon Iron ◽  
The Individual

This study proposed that the physicochemical effects of common dyebath auxiliaries on the bulk dye solution as well as on the iron surface can influence the reductive discoloration of effluent containing Acid Orange 7 (AO7) dye using high-carbon iron filings. Sodium chloride increased the discoloration rate because of the pitting corrosion on the iron surface, triggered by chloride anion. ‘Salting out’ effect of ammonium sulfate improved the reaction rate up to a certain concentration, beyond which it could compete with dye molecules for the reactive sites, as revealed by formed sulfite and sulfide. Urea drastically reduced the discoloration rates by its chaotropic effect on the bulk solution and by wrapping around the iron surface. Organic acids, namely acetic acid and citric acid, stimulated iron corrosion to improve the discoloration rates. The discoloration reaction was biphasic with an initial fast reaction phase, where in every case more than 70% discoloration was observed within 5 min of reaction, preceding a slow reaction phase. The experimental data could be well described using biphasic kinetics equation (R2&gt; 0.997 in all cases) and a biphasic equation was developed considering the individual impact of co-existing auxiliaries on AO7 discoloration.

FAMILIAL GOITRE WITH ABSENCE OF THYROGLOBULIN AND SYNTHESIS OF THYROID HORMONES FROM THYROIDAL ALBUMIN

1974 ◽  
Vol 60 (3) ◽  
pp. 389-397 ◽  
Author(s):  
K. B. DESAI ◽  
M. N. MEHTA ◽  
M. C. PATEL ◽  
S. M. SHARMA ◽  
L. RAMANNA ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Radioactive Iodine ◽  
Gradient Centrifugation ◽  
Gel Filtration ◽  
Sucrose Density Gradient ◽  
Starch Gel Electrophoresis ◽  
Sucrose Density Gradient Centrifugation ◽  
Salting Out ◽  
Immunological Tests ◽  
Starch Gel

SUMMARY Two siblings, a brother (H. B.) and a sister (R. B.) with long standing goitres were investigated. Radioactive iodine uptake by the thyroid was increased and a significant portion of the plasma radioactive iodine was not extractable with butanol. Chromatography of butanol extracts of serum after radioactive iodine administration showed distinct peaks of triiodothyronine and thyroxine. Microscopic examination of the surgical specimens of the goitres showed Hürthle cell carcinoma with follicles devoid of colloid in both specimens. Sucrose density gradient centrifugation, gel filtration on Sephadex G-200, salting out procedures, starch gel electrophoresis and immunological tests of the supernatant soluble fraction of thyroid homogenates showed a lack of thyroglobulin. Further fractionation of the soluble proteins showed that albumin was apparently involved in the synthesis of thyroid hormones in the absence of thyroglobulin.

scholarly journals Function of the CysD domain of the gel-forming MUC2 mucin

2011 ◽  
Vol 436 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Daniel Ambort ◽  
Sjoerd van der Post ◽  
Malin E. V. Johansson ◽  
Jenny MacKenzie ◽  
Elisabeth Thomsson ◽  
...  
Keyword(s):  
Fusion Proteins ◽  
Disulfide Bonds ◽  
Tandem Repeats ◽  
Gel Filtration ◽  
Middle Part ◽  
Domain Of Unknown Function ◽  
Cross Links ◽  
Native Gel ◽  
The Individual ◽  
Covalent Nature

The colonic human MUC2 mucin forms a polymeric gel by covalent disulfide bonds in its N- and C-termini. The middle part of MUC2 is largely composed of two highly O-glycosylated mucin domains that are interrupted by a CysD domain of unknown function. We studied its function as recombinant proteins fused to a removable immunoglobulin Fc domain. Analysis of affinity-purified fusion proteins by native gel electrophoresis and gel filtration showed that they formed oligomeric complexes. Analysis of the individual isolated CysD parts showed that they formed dimers both when flanked by two MUC2 tandem repeats and without these. Cleavages of the two non-reduced CysD fusion proteins and analysis by MS revealed the localization of all five CysD disulfide bonds and that the predicted C-mannosylated site was not glycosylated. All disulfide bonds were within individual peptides showing that the domain was stabilized by intramolecular disulfide bonds and that CysD dimers were of non-covalent nature. These observations suggest that CysD domains act as non-covalent cross-links in the MUC2 gel, thereby determining the pore sizes of the mucus.

scholarly journals Purification of a cortical complex containing two unconventional actins from Acanthamoeba by affinity chromatography on profilin-agarose.

1994 ◽  
Vol 127 (1) ◽  
pp. 107-115 ◽  
Author(s):  
L M Machesky ◽  
S J Atkinson ◽  
C Ampe ◽  
J Vandekerckhove ◽  
T D Pollard
Keyword(s):  
Gel Filtration ◽  
Protein Sequences ◽  
Rabbit Muscle ◽  
Muscle Actin ◽  
Novel Proteins ◽  
Cell Extracts ◽  
A Value ◽  
Stokes Radius ◽  
Globular Particle ◽  
Stoichiometric Complex

We identified four polypeptides of 47, 44, 40, and 35 kD that bind to profilin-Sepharose and elute with high salt. When purified by conventional chromatography using an antibody to the 47-kD polypeptide, these four polypeptides copurified as a stoichiometric complex together with three additional polypeptides of 19, 18, and 13 kD that varied in their proportions to the other polypeptides. Partial protein sequences showed that the 47-kD polypeptide is a homologue of S. pombe act2 and the 44-kD polypeptide is a homologue of S. cerevisiae ACT2, both unconventional actins. The 40-kD polypeptide contains a sequence similar to the WD40 motif of the G beta subunit of a trimeric G-protein from Dictyostelium discoideum. From partial sequences, the 35-, 19-, and 18-kD polypeptides appear to be novel proteins. On gel filtration the complex of purified polypeptides cochromatograph with a Stokes' radius of 4.8 nm, a value consistent with a globular particle of 220 kD containing one copy of each polypeptide. Cell extracts also contain components of the complex that do not bind the profilin column. Affinity purified antibodies localize 47- and 18/19-kD polypeptides in the cortex and filopodia of Acanthamoeba. Antibodies to the 47-kD unconventional actin cross-react on immunoblots with polypeptides of similar size in Dictyostelium, rabbit muscle, and conventional preparations of rabbit muscle actin but do not react with actin.

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