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At least 19 recordsLinked to original sources
PubMedDate not supplied

Reevaluation of the ammonium sulfate assay for DNA antibody.

The ammonium sulfate assay has recently come under criticism for alleged inability to detect low avidity antibody to DNA. The results of this study verify that a small percentage of antibody binding is not detected when this assay is performed under the conditions generally used. However, when the values obtained by the ammonium sulfate assay were compared to those obtained by other assays on sera of known avidity for DNA, it was concluded that ammonium sulfate does not selectively dissociate low avidity antibody from DNA. Conditions of incubation buffer and duration, pH, concentration of reactants, and molecular weight of the antigen are described for optimal detection of DNA antibody by the ammonium sulfate assay.

Ammonium Sulfate↗
PubMed1976

Antibodies against Escherichia coli O antigen. Antibody amounts and avidities measured with ammonium sulfate precipitation technique.

The ammonium sulfate precipitation (ASP) technique, modified Farr assay, has been utilized to study antibodies to Escherichia coli O2, O4, O6 and O75 antigens the induction of which could not be ascribed to the effect of a defined antigen. It was noted that the antibody titers against the O6 antigen in children, 0.1-2.5 years of age, were of lower magnitude than the others, significantly for the O2 and O4 antigens. Comparison between boys and girls under and over 1.0 year of age revealed higher titers in sera from girls and in the older children. However, significant differences were obtained only in a few instances. The antibody avidities were in most cases low and no correlation was found between antibody quantity and avidity. In consecutive samples from adults a varying pattern of antibodies to the O6 and O75 antigens was observed.

Adolescent↗
PubMed1977

Fractionation of rhodopsin and other components in the rod outer segment membrane by ammonium sulfate salting-out.

Purified bovine rod outer segment membrane was solubilized in a mixture of 1.5% cholic acid/20% saturated ammonium sulfate and 0.05 M phosphate buffer (pH 7.5). The solubilized rod outer segment membrane was fractionated with ammonium sulfate and 70--90% of rhodopsin (A278/A498= 1.6--1.9) was recovered in the fraction of 50 to 60% saturation with ammonium sulfate, giving a highly concentrated solution of purified rhodopsin (A1CM 498 = 83). By the method of ammonium sulfate salting-out, the solubilized rod outer segment membrane was divided into several fractions without a loss of components. The components in each fraction were examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Rhodopsin and opsin amounted to 93% of the total protein in the membrane. Other proteins with molecular weights of 46 000, 52 000, 56 000, 70 000, 95 000, 105 000, 130 000 and 270 000 were also detected. Most of phospholipids in the rod outer segment membrane remained in the supernatant above 60% saturation with ammonium sulfate.

Ammonium Sulfate↗
PubMed1978

[Possible role of ammonium sulfate in inducing invertase biosynthesis in plants].

The induction of invertase from beetroot plants and wheat shoots was studied using the "ageing tissues" technique. It was found that ammonium sulfate at concentration 0.001 M enhances invertase induction. This effect of ammonium sulfate was not revealed when the preparations were pretreated by actidione, puromycin and chloramphenicol. A possibility of activation of invertase induction by ammonium sulfate is discussed.

Ammonium Sulfate↗
PubMed1977

Characterization of microsomal electron transport components from control, phenobarbital- and 3-methylcholanthrene-treated mice. II. Improved resolution and quantitation of major components in ammonium sulfate fractions from total liver microsomes.

Quantitation of microsomal components in ammonium sulfate fractions using a high-resolution sodium dodecyl sulfate-polyacrylamide gel electrophoresis system, and a comparison of these results with those from similar experiments on total liver microsomes has enabled us to identify and better characterize the interactions between microsomal electron transport components. It was found that: (1) phenobarbital decreased the amount of one protein component of approximately 50 000 molecular weight while increasing a component of very similar molecular weight; (2) only two proteins appeared to be associated with CO binding; (3) another protein of approximately 68 000 molecular weight, one of the glycoproteins found in liver microsomes, appears to be induced by phenobarbital pretreatment; (4) the induction of NADPH-cytochrome c reductase activity after phenobarbital pretreatment is not dependent on an increase in the known NADPH-dependent flavoprotein, but rather on the increase in some component found predominately in our most soluble sub-microsomal fraction. A very good separation of the above components was achieved by ammonium sulfate fractionation, e.g. simply on the basis of their solubility. This and the fact that the more-or-less soluble proteins were induced by phenobarbital or 3-methylcholanthrene respectively indicate that the solubility of membrane proteins plays a major role in the structure and function of microsomal membranes.

Ammonium Sulfate↗
PubMed1976

Densitometric quantitation of neutral lipids on ammonium sulfate impregnated thin-layer chromatograms.

A procedure is described which extends the densitometric quantitation of phospholipids on ammonium sulfate impregnated thin-layer chromatograms by Gluck et al. to include total lipid, free and esterified cholesterol, free fatty acid and triglyceride. Lipids separated on thin-layer plates containing silica gel G impregnated with ammonium sulfate were charred upon heating and absorbance was measured densitometrically. Thus, the necessity of spraying or submersing in a charring agent was eliminated, uniform charring became possible, and quantitation over a wider range of sample sizes than most densitometric procedures was obtained. One linear relationship existed for concentrations of standards over the range of 0.0-3.0 mug and another line from 4.0-50.0 mug. Both accuracy and precision of the method were highly reliable.

Ammonium Sulfate↗
PubMed1978

An immunoglobulin E assay using radiolabelled Fab' and ammonium sulfate.

An immunochemical assay is described in which a radiolabelled antibody fragment, Fab', is bound specifically to immunoglobulin E (IgE), and precipitated with ammonium sulfate. The radioactivity in the precipitate is a measure of the amount of IgE in the sample. Results for six serum samples are compared using the double antibody and ammonium sulfate methods as well as the PRIST.

Ammonium Sulfate↗
PubMed1975

Treatment of intercostal neuralgia with 10 per cent ammonium sulfate.

Intercostal nerves were injected with 10 per cent annomium sulfate in 41 patients (52 total sets of injections) for management of intercostal neuralgia from radical mastectomy (six blocks), thoracotomy (20 blocks), or unknown etiology (26 blocks). Five patients failed to return for follow-up evaluation and could not be located. Sixty per cent (28/47) of the treatments produced complete or nearly complete (excellent) relief of pain. Excellent pain relief persisted for more than 20 days after 22 treatments and for more than 90 days after seven treatments. Postblock neuritis never occurred. We conclude that intercostal nerve block with 10 per cent ammonium sulfate effectively relieves intercostal neuralgia and is not associated with postblock neuritis. We therefore believe that ammonium sulfate nerve blocks should be administered for treatment of intercostal neuralgia before phenol or alcohol nerve blocks or a surgical procedure.

Ammonium Sulfate↗
PubMed1975

Comparison of dextran-coated charcoal and ammonium sulfate in the radioimmunoassay of estrogens.

A comparison was made between the use of ammonium sulfate (AS) and Dextran coated charcoal (DCC) to separate free and antibody-bound estrogens in the RIA of estrone and estradiol in serum. Under the conditions tested, AS yielded values which were approximately twice those obtained using DCC. This difference was found for both estrogens, using male and female serum and regardless of whether the estrogens were separated from one another by means of the Girard reagent or TLC. There was no significant difference in the sensitivity, accuracy or usable range of the standard curve or in the water-blank for the two procedures.

Ammonium Sulfate↗
PubMed1976

Preparation of human immunoglobulin by ammonium sulfate precipitation.

Crude IgG precipitated from plasma by the addition of an equal volume of 4 M ammonium sulfate was fractionated on DEAE-cellulose column to obtain pure IgG as shown by disc electrophoresis, immunoelectrophoresis and gel filtration. The processed IgG was free of plasmin and plasminogen and did not undergo fragmentation or aggregation on storage at 40 degrees C for at least 4 weeks. The anticomplement activity was low and the antibody activity was retained.

Ammonium Sulfate↗
PubMed1975

Ammonium sulfate precipitation as a tool for the study of androgen receptor proteins in rat prostate and mouse kidney.

Ammonium sulfate precipitation has been used for the separation of bound and free steroids in rat prostate and mouse kidney cytosol equilibrated with tritiated androgens. A high affinity, low capacity binding protein has been identified in the 35% saturation precipitate. Biochemical and physiological data indicate that this protein is identical with the previously described 8-10 S androgen receptor. It has been demonstrated that this receptor protein binds 17 beta - hydroxy-5alpha-androstan-3-one (DHT) and testosterone in both tissues. The apparent dissociation constant (Kd) of the prostatic receptor for DHT and of the renal receptor for testosterone is 1-2 nM. The number of binding sites equals 57 and 23 fmoles/mg protein in prostate and kidney respectively. Dterminations of apparent inhibition constants (Ki) for 26 steroidal and non-steroidal compounds suggest that the binding sites in these tissues is similar or identical.

Ammonium Sulfate↗
PubMed1979

A simple, large scale process for purifying human urinary kallikrein, based on reverse osmosis and ammonium sulfate precipitation.

A simple, large scale process for the purification of human urinary kallikrein is described which is based upon concentration by reverse osmosis, ammonium sulfate precipitation, and gel filtration on a column of Sephadex-G-150. The yield in protein is higher than any reported in the literature to this date; the purified enzyme seems to be identical to that reported by Figueiredo and Mares-Guia at the Kinin-Symposium in Paris, 1978, based on the procedure of Hial, et al., (1974).

Amino Acids↗
PubMed1976

The kinetics of protein salting-out: precipitation of yeast enzymes by ammonium sulfate.

Protein solubility can be adequately represented by the classical Cohn equation for the salting-out of alcohol dehydrogenase and fumarase from clarified yeast homogenate with ammonium sulfate. However, the constant beta in this equation is a function of the contacting procedure employed. The kinetics of continuous salting-out were similar for alcohol dehydrogenase and fumarase. The overall rate equation for precipitation had a variable order which was high initially, up to 3.1, but approached unity on completion of precipitation. This was followed by a partial resolution stage which was first order with respect to the concentration driving force. Precipitate particle size was estimated as 0.5 to 5 mum with continuous flow precipitation producing the largest particles.

Alcohol Oxidoreductases↗
PubMedDate not supplied

[Assay of the activity of horseradish peroxidase antibodies using ammonium sulfate technique (author's transl)].

The antigen binding capacity (ABC) of mouse and rabbit antisera to horseradish peroxidase (HRP) was measured by the Farr technique, originally introduced for bovine serum albumin. Results obtained by this method are independent of other antibody interactions (precipitation, formation of immune complexes, effect on enzyme activity). Commercially available HRP has variable solubility in ammonium sulfate solutions; almost 40% was precipitated at 50% saturation. Accordingly, the fraction of HRP soluble at 60% saturation was used, and this was labelled with 125I2 using the HRP oxidizing activity. Under these test conditions, accurate and reproducible results were obtained with protein concentrations (as N/ml) of the order to 0.07 mug (antibody) and 0.01 mug (antigen) respectively. This high sensitivity is superior to that achieved by passive hemagglutination, especially when titrating antibody levels in mouse sera.

Ammonium Sulfate↗
PubMed1979

[Studies on lytic enzyme activities of bacteria and streptomycetes against Candida guilliermondii after partial purification with ammonium sulfate from shaking- and fermentation cultures (author's transl)].

Two bacteria and two streptomycetes strains, capable to degrade cell walls of Candida guilliermondii, were isolated from soils. Growth and enzyme production of these strains were investigated on synthetic and complex media in shaking culture and under fermentation conditions. The isolated microorganisms possessed lytic enzyme activities against living and autoclaved yeast cells. The lytic enzyme complex of the culture medium of microorganisms was partially purified by ammonium sulfate precipitation. After this purification step the lytic enzyme activity of the bacteria was higher that of the streptomycetes towards the control. The lytic enzyme activity of the bacteria was thermostable (30 min, 80 degrees C), that of streptomycetes thermolable (inactive - greater than 40 degrees C). The pH-optimum of the bacteria enzymes was in the range of 5.0-7.5, that of the streptomycetes 5.0-8.5.

Bacteria↗