Ammonium sulfate Subject

Blue tungsten oxide and combiaations thereof (106—113) have been the subject of a number of patents, as have copper(II) fluoborate (114) and alkaH metal or ammonium sulfate-hydrogen sulfate catalysts (115,116). 

Dibydropteridine reductase (from sbeep liver) [9074-11-7] Mr 52,000 [EC 1.6.99.7]. Purified by fractionation with ammonium sulfate, dialysed versus tris buffer, adsorbed and eluted from hydroxylapatite gel. Then run through a DEAE-cellulose column and also subjected to Sephadex G-lOO filtration. [Craine et al. J Biol Chem 247 6082 1972.]... 

Purification of photoprotein. The dialyzed photoprotein solution was centrifuged to remove precipitates, and then subjected to fractional precipitation by ammonium sulfate, taking a fraction precipitated between 30% and 50% saturation. The protein precipitate was dissolved in 50 ml of 10 mM sodium phosphate, pH 6.0, containing 0.1 mM oxine ( pH 6.0 buffer ), dialyzed against the same buffer, and the dialyzed solution was adsorbed on a column of DEAE-cellulose (2.5 x 13 cm) prepared with the pH 6.0 buffer. The elution was done by a stepwise increase of NaCl concentration. The photoprotein was eluted at 0.2-0.25 M NaCl and a cloudy substance (cofactor 1) was eluted at about 0.5 M NaCl. The photoprotein fraction was further purified on a column of Sephadex G-200 or Ultrogel AcA 34 (1.6 x 80 cm) using the pH 6.0 buffer that contained 0.5 M NaCl. 

Having treated this subject more in the manner of a poet than a scientist [savant], the result is that it is difficult to know exactly his [Dumas s] thought.. . . Whether this statue should be in bronze, in marble, or in ivory the material is of little importance, says M. Dumas it is always the same statue, the same type. In effect, it little matters that this sulfate is a salt of copper, or of lead or of iron it always belongs to the sulfate type. But where do we stop ammonium sulfate, sulfuric ether, alum, do they belong to the sulfate type 54... 

Aqueous solutions of ammonium sulfate and ammonium bisulfate were deposited on Fluoropore filters, placed in the direct insertion probe, and analyzed in the chemical ionization mode (H2O reagent) gas. The samples were heated from 100°C to 330 C at 15 C/minute. No sample ions were observed under these anlaysis conditions, even when several micrograms of ammonium salts were analyzed. The thermal decomposition of ammonium salts of sulfate has been the subject of many studies. (29,30) Some pathways include sulfuric acid production at one stage of the decomposition while others suggest ammonia, SO2 and SO3 are the products. None of these accurately simulate the conditions (temperature, pressure, gas flow) present in our chemical ionization source. However, no sulfuric acid ions (H3SO4+, etc.) were ob-served... 

A cell extract was subjected to ammonium sulfate fractionation and the dialyzed protein was then poured through the affinity column which held the cytidine deaminase molecules because of their affinity for the cytidine structures that were bound to the agarose. 

For example, a crude cell extract is treated by slow addition of dry, solid, high-purity ammonium sulfate in order to achieve a change in salt concentration from 0 to 25% in ammonium sulfate, is gently stirred for up to 60 minutes, and is subjected to centrifugation at 20,000 X g. The precipitate that separates upon centrifugation and the supernatant are analyzed for the desired protein. If the protein is still predominantly present in the supernatant, the salt concentration is increased from 25 to 35%. This process of ammonium sulfate addition and centrifugation is continued until the desired protein is salted out. 

A large scale preparation of E. coli 045 was subjected to enzyme purification using the assay for 3,5-epimerase. Protamin sulfate precipitation, ammonium sulfate fractionation was followed by DEAE-chroma-tography. The fraction containing enzymatic activity, as measured by tritium exchange, was eluted from the DEAE column early. This fraction was incapable of producing any net synthesis of TDP-6-deoxy-L-... 

The most common protein precipitation technique involves the use of ammonium sulphate, which has been the subject of a recent review (3). The widespread use of ammonium sulfate can be ascribed to the fact that it is very soluble (saturated solutions have a concentration in the region of AM), the density of solutions do not compromise collection of precipitates by centrifugation and its use does not promote denaturation of proteins. The addition of ammonium sulfate will cause a neutralization of the surface charge of the protein and a decrease in the effective concentration of water leading to a decrease in protein solvent interactions. 

The only non-mammalian /8-glucuronidase that has been subjected to systematic purification is the enzyme from sheep-rumen microorganisms. After repeated ammonium sulfate fractionation, Marsh101 obtained a colorless preparation with a specific activity of 1,900 (400-fold purification and 2% recovery). The final product gave a linear, specific-property, solubility test from which a figure of 2,200 was derived for the ultimate specific activity of the enzyme, but it was considered that the enzyme may have formed a solid solution with inactive protein. 

If a further purification is desired, then the supernatant (above) can be subjected to ammonium sulfate fractionation, gel filtration on Sephadex G-200, and finally on a-aminopropane-agarose affinity column. On polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate, the final product migrated as a single band with an estimated molecular weight of 113,000. Upon sedimentation equilibrium velocity ultracentrifugation, an estimated molecular weight value of near 117,000 was obtained. 

Kulle, T.J., L.R.Sauder, F.Shanty, H.D.Kerr, B.P.Farrell, W.R.Miller, and J.H.Milman. 1984. Sulfur dioxide and ammonium sulfate effects on pulmonary function and bronchial reactivity in human subjects. Am. Ind. Hyg. Assoc. J. 45(3) 156—161. 

As Streptomyces contain high proportions of proteases, a protease inhibitor, diphenylcarbamoyl chloride, was added to the buffer during purification of the dTDP-dihydrostreptose synthase. A partially purified, enzyme preparation from S. griseus could be obtained by removal of nucleic acids with streptomycin and fractionation with ammonium sulfate.40 However, when this enzyme preparation was subjected to gel filtration on a column of Sephadex G-100, enzyme activity was completely lost. By combining certain fractions of the column eluate, enzyme activity could be partially restored. 

The substituted phenols are practically insoluble in water however, being phenols, they readily form salts with organic and inorganic bases, most of which are water-soluble. Since they must utilize water as a carrier in order to be selective and yet penetrate the leaf cuticle, they all respond to activation by buffering on the acid side of neutrality. Ammonium sulfate is the common compound used to bring about this activation. In this water-soluble form they are subject to leaching and runoff from the soil. Some, but not all, of the chlorophenols are oxidized by the soil microflora. For example, 2,6-dichlorophenol is readily destroyed while the 2,3-, 3,4-, and 3,5-dichlorophenols persist for long periods (15). 

Fe(ll)(H20)6](NH4)2(S04)2, ferrous ammonium sulfate Note This is subject to slow air oxidation)... 

As another example, imagine that an S-100 fraction has been prepared, ammonium sulfate has been added, and the fraction that precipitates between 30 and 50% has been obtained. This sample is subjected to affinity and ion-exchange chromatography. Have these procedures been successful in removing extraneous proteins While it is possible to answer this question by a determination of total protein content, it may be more informative to analyze each of the samples for its constituent proteins. 

Several modifications of the above protocol have been described for eco purification. These are very useful for the purification of eco variants as they consist of a gentler series of purification steps. Following the acidification step, the protein is dialyzed into distilled water and subjected to a 65% (w/v) ammonium sulfate precipitation. The insoluble fraction is resuspended in distilled water, dialyzed into 10 mM Tris pH 8.0, and concentrated. The resulting protein is purified to homogeneity by FPLC chromatography on a Mono-Q anion exchange column (Pharmacia) with a slow gradient of 0-15% NaCl. 

The supernatant was subjected to fractional precipitation with ammonium sulfate (step 5) and then with acetone (step 6). PTTH was recovered in the precipitates with 35-55% acetone, while bombyxins were recovered with 55-75% acetone. The 35-55% acetone precipitates were subsequently purified through five steps of conventional chromatography gel filtration on Sephadex G-50 with 0.5M Tris-HCl (pH 8.5) (step 7), anion exchange on DEAE-Sepharose C1-6B with 0.2M sodium acetate (pH 5.2)(step 8), cation exchange on CM-Sepharose C1-6B 0.1-0.5M NaCl in 0.05M sodium acetate (pH 5.2) (step 9), Hydrophobic adsorption on Octyl-Sepharose C1-4B with 4M ammonium acetate, 0.2M ammonium acetate and 40% acetonitrile in 0.2M ammonium acetate (step 10) and gel filtration on Sephadex G-75 with O.OIM phosphate buffer containing 0.2M NaCl and 2% butanol (step 11). 

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