scholarly journals PURIFICATION AND CONCENTRATION OF ENTEROKINASE

1939 ◽  
Vol 22 (4) ◽  
pp. 447-450 ◽  
Author(s):  
M. Kunitz
Keyword(s):  
Ammonium Sulfate ◽  
Fractional Precipitation ◽  
Ph Conditions ◽  
Concentrated Solution

A concentrated solution of purified enterokinase is conveniently prepared from the fluid contents of pigs' duodena by means of fractional precipitation with ammonium sulfate under the proper pH conditions.

AN ANTIVIRAL SUBSTANCE FROM PENICILLIUM CYANEO-FULVUM BIOURGE: I. PRODUCTION AND PARTIAL PURIFICATION

1965 ◽  
Vol 11 (6) ◽  
pp. 913-919 ◽  
Author(s):  
Patricia M. Cooke ◽  
J. W. Stevenson
Keyword(s):  
Ammonium Sulfate ◽  
Ethyl Alcohol ◽  
Antiviral Agent ◽  
Partial Purification ◽  
Fractional Precipitation ◽  
Antiviral Substance

Penicillium cyaneo-fulvum Biourge, which produces a toxin-neutralizing substance, has been shown to produce a separate and distinct antiviral agent. The two products may be separated in a semipurified state by fractional precipitation with ammonium sulfate and ethyl alcohol.

scholarly journals Water uptake of biomass burning aerosol at sub- and supersaturated conditions: closure studies and implications for the role of organics

2010 ◽  
Vol 10 (12) ◽  
pp. 29853-29895 ◽  
Author(s):  
U. Dusek ◽  
G. P. Frank ◽  
A. Massling ◽  
K. Zeromskiene ◽  
Y. Iinuma ◽  
...  
Keyword(s):  
Ammonium Sulfate ◽  
Water Uptake ◽  
Biomass Burning ◽  
Volume Fraction ◽  
Minor Importance ◽  
Hygroscopic Growth ◽  
Controlled Burning ◽  
Surface Active ◽  
Concentrated Solution ◽  
Biomass Burning Particles

Abstract. We investigate the CCN activity of freshly emitted biomass burning particles and their hygroscopic growth at a relative humidity (RH) of 85%. The particles were produced in the Mainz combustion laboratory by controlled burning of various wood types, peat and grass. The water uptake at sub- and supersaturations is parameterized by deriving a soluble volume fraction (ε). It is defined as the volume fraction of ammonium sulfate in the total aerosol material, which would be sufficient to explain the observed water uptake. For the wood burns, soluble volume fractions are low, generally around 0.11. This translates to a hygroscopicity parameter κ (another widely used parameterization; cf. Petters and Kreidenweis, 2007) of around 0.07. The main emphasis of this study is a comparison of ε derived from measurements at sub- and supersaturated conditions εG and εCCN), in order to see whether the water uptake at 85% RH can predict the CCN properties of the biomass burning particles. Differences in εG and εCCN can arise through solution non-idealities, the presence of slightly soluble or surface active compounds, or non-spherical particle shape. We find that εG and εCCN agree within experimental uncertainties (of around 30%) for particle sizes of 100 and 150 nm; only for 50 nm particles is εCCN larger than εG by a factor of 2. The magnitude of this difference and its dependence on particle size is consistent with the presence of surface active organic compounds. These compounds mainly facilitate the CCN activation of small particles, which form the most concentrated solution droplets at the point of activation. The 50 nm particles, however, are only activated at supersaturations higher than 1% and are therefore of minor importance as CCN in ambient clouds. By comparison with the actual chemical composition of the biomass burning particles, we estimate that the hygroscopicity of the organic fraction is roughly 1/3 that of ammonium sulfate and can be represented by κ = 0.15–0.2.

scholarly journals PURIFICATION AND CRYSTALLIZATION OF DIPHTHERIA ANTITOXIN

1942 ◽  
Vol 25 (3) ◽  
pp. 465-485 ◽  
Author(s):  
John H. Northrop
Keyword(s):  
Molecular Weight ◽  
Ammonium Sulfate ◽  
Diphtheria Toxin ◽  
Soluble Fraction ◽  
Thin Plates ◽  
Fractional Precipitation ◽  
Protein Nitrogen ◽  
Sedimentation Constant ◽  
Diphtheria Antitoxin ◽  
Pure Protein

Purified preparations of diphtheria antitoxin have been obtained by digestion of the toxin-antitoxin complex with trypsin, followed by fractional precipitation with ammonium sulfate. The various fractions obtained in this way are all 90 per cent or more precipitated by diphtheria toxin but combine with different quantities of the toxin. The fraction precipitated between 0.33 and 0.5 saturated ammonium sulfate is homogeneous by electrophoresis and ultracentrifuge but does not have constant solubility. A small amount of a more soluble fraction has been obtained which does have constant solubility and satisfies the criteria of a pure protein. This protein crystallizes readily in poorly formed thin plates. It is very unstable and reverts to a less soluble non-crystallizable form. It has a sedimentation constant of 5.7 x 10–13 and a molecular weight of 90,500. It has an antitoxic value of 700–900 flocculation units per mg. protein nitrogen and has an antitoxic value by the protection test of about 700 units per mg. protein nitrogen. The precipitation range of the purified antitoxin with purified toxin is much wider than that with crude preparations.

Fractional Precipitation of Proteins by Ammonium Sulfate

2006 ◽  
Vol 2006 (1) ◽  
pp. pdb.prot4309 ◽  
Author(s):  
Richard J. Simpson
Keyword(s):  
Ammonium Sulfate ◽  
Fractional Precipitation

scholarly journals ISOLATION, CRYSTALLIZATION, AND PROPERTIES OF SWINE PEPSINOGEN

1938 ◽  
Vol 21 (4) ◽  
pp. 501-540 ◽  
Author(s):  
Roger M. Herriott
Keyword(s):  
Ammonium Sulfate ◽  
Optical Rotation ◽  
Amino Nitrogen ◽  
Sulfate Solution ◽  
Fractional Precipitation ◽  
Specific Optical Rotation ◽  
Stability Range ◽  
Protein Nitrogen ◽  
Elementary Analysis ◽  
Reaction Conversion

1. A method is described for the preparation of pepsinogen from swine gastric mucosae which consists of extraction and fractional precipitation with ammonium sulfate solutions followed by two precipitations with a copper hydroxide reagent under particular conditions. Crystallization as very thin needles takes place at 10°C., pH 5.0 and from 0.4 saturated ammonium sulfate solution containing 3–5 mg. protein nitrogen per milliliter. 2. Solubility measurements, fractional recrystallization, and fractionation experiments based on separation after partial heat or alkali denaturation and after partial reversal of heat or alkali denaturation failed to reveal the presence of any protein impurity. 3. The properties of the enzymatically inactive pepsinogen were studied and compared with the properties of crystalline pepsin. The properties of pepsinogen which are similar to those of pepsin are: molecular weight, absorption spectrum, tyrosine-tryptophane content, and elementary analysis. The properties in which they differ are: enzymatic activity, crystalline form, amino nitrogen, titration curve, pH stability range, specific optical rotation, isoelectric point, and the reversibility of heat or alkali denaturation. 4. Conversion of pepsinogen into pepsin at pH 4.6 was found to be autocatalytic; i.e., the pepsin formed catalyzes the reaction. Conversion of pepsinogen into pepsin is accompanied by the splitting off of a portion of the molecule containing 15–20 per cent of the pepsinogen nitrogen.

scholarly journals CRYSTALLINE HEXOKINASE (HETEROPHOSPHATESE)

1946 ◽  
Vol 29 (6) ◽  
pp. 393-412 ◽  
Author(s):  
M. Kunitz ◽  
Margaret R. McDonald
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Enzymatic Activity ◽  
Physicochemical Properties ◽  
Ammonium Sulfate ◽  
Filter Cake ◽  
Magnesium Ions ◽  
Fractional Precipitation ◽  
Hexokinase Activity ◽  
Protein Nature

1. Crystalline hexokinase has been isolated from baker's yeast. 2. Crystalline hexokinase is a protein of albumin type of a molecular weight of 96,000. Its isoelectric point is at about pH 4.8. 3. The method of isolation consists in separating the proteins of an aqueous extract of toluene-treated yeast by means of fractional precipitation with ammonium sulfate and with alcohol. 4. The procedure involves also the separation of several crystalline proteins, including one yellow crystalline protein, which do not possess hexokinase activity. The biological and the physicochemical properties of these proteins are still under investigation. 5. The crystallization of hexokinase proceeds at about 5°C. in the presence of ammonium sulfate and dilute phosphate buffer pH 7.0. 6. Crystalline hexokinase becomes relatively pure after 2 or 3 recrystallizations as tested by solubility, sedimentation in the ultracentrifuge, and electrophoresis. The enzymatic activity remains constant on repeated crystallization. 7. The enzymatic activity is associated with the protein nature of the material. Inactivation is accompanied by denaturation of the protein. 8. Crystalline hexokinase is relatively stable when stored in the form of crystalline filter cake. Solutions of hexokinase in dilute buffers are most stable at pH 5.0. 9. Crystalline hexokinase requires the presence of magnesium ions for its catalytic activity.

The Coagulation Abnormalities in Systemic Lupus Erythematosus

1968 ◽  
Vol 20 (03/04) ◽  
pp. 457-464 ◽  
Author(s):  
L Gonyea ◽  
R Herdman ◽  
R. A Bridges
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Ammonium Sulfate ◽  
Lupus Erythematosus ◽  
Anticoagulant Activity ◽  
Species Specificity ◽  
Sensitive Assay ◽  
Systemic Lupus ◽  
Coagulation Abnormalities

SummaryAn anticoagulant occurring in 4 of 6 patients with SLE has been demonstrated by a sensitive assay utilizing an ammonium sulfate fraction of serum. The anticoagulant functions as an inhibitor of the activation of prothrombin. No species specificity was demonstrable. The inhibitor behaves clinically and chromatographically as an immunoglobulin, although an attempt to demonstrate directly the antibody nature of the inhibitor was not successful.A severe, apparently independent, decrease in the level of prothrombin was observed in the patient with hemorrhagic symptoms. In contrast to the anticoagulant activity, the low prothrombin has persisted during treatment.

Extraction and Partial Purification of Protease from Bilimbi (Averrhoa bilimbi L.)

2013 ◽  
Vol 10 (2) ◽  
pp. 29
Author(s):  
Normah Ismail ◽  
Nur' Ain Mohamad Kharoe
Keyword(s):  
Molecular Weight ◽  
Protein Content ◽  
Ammonium Sulfate ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Protease Activity ◽  
Protein Concentration ◽  
Temperature Stability ◽  
Partial Purification ◽  
Ammonium Sulfate Precipitation

Unripe and ripe bilimbi (Averrhoa bilimbi L.) were ground and the extracted juices were partially purified by ammonium sulfate precipitation at the concentrations of 40 and 60% (w/v). The collected proteases were analysed for pH, temperature stability, storage stability, molecular weight distribution, protein concentration and protein content. Protein content of bilimbi fruit was 0.89 g. Protease activity of both the unripe and ripe fruit were optimum at pH 4 and 40°C when the juice were purified at 40 and 60% ammonium sulfate precipitation. A decreased in protease activity was observed during the seven days of storage at 4°C. Molecular weight distribution indicated that the proteases protein bands fall between IO to 220 kDa. Protein bands were observed at 25, 50 and 160 kDa in both the unripe and ripe bilimbi proteases purified with 40% ammonium sulfate, however, the bands were more intense in those from unripe bilimbi. No protein bands were seen in proteases purified with 60% ammonium sulfate. Protein concentration was higher for proteases extracted with 40% ammonium sulfate at both ripening stages. Thus, purification using 40% ammonium sulfate precipitation could be a successful method to partially purify proteases from bilimbi especially from the unripe stage. 

Effect of Methionine and Ammonium Sulfate upon Performance of Ruminants Fed High Corn Rations

1973 ◽  
Vol 36 (6) ◽  
pp. 1186-1190 ◽  
Author(s):  
K. K. Bolsen ◽  
Walter Woods ◽  
Terry Klopfenstein
Keyword(s):  
Ammonium Sulfate
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