PREPARATION OF GLUTENIN IN UREA SOLUTIONS

1931 ◽  
Vol 5 (3) ◽  
pp. 355-374 ◽  
Author(s):  
W. H. Cook ◽  
C. L. Alsberg
Keyword(s):  
Magnesium Sulphate ◽  
Dispersion Medium ◽  
Room Temperature ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Urea Solution ◽  
Previous Exposure ◽  
Hydrogen Ion Concentration ◽  
Nitrogen Contents ◽  
Urea Method

A new method has been developed for preparing glutenin, using concentrated urea solution as a dispersion medium. The starch is removed from the dispersion by passing it through a Sharpies supercentrifuge. The glutenin is then removed from the gliadin by precipitation: (a) by adding magnesium sulphate to about 0.17 of saturation; or (b) by adding water until the urea is diluted to about 10% concentration. Alcohol precipitation is unsatisfactory, since the glutenin loses much of its original solubility. Drying, even at room temperature, renders glutenin insoluble in 30% urea solution. Different samples of glutenin isolated by the urea method have similar amide and arginine nitrogen contents. The amount of these constituents is intermediate between the values reported for glutenin isolated from alkali, and that isolated from acid. While urea solutions denature some proteins, they affect glutenin less than dilute alkalies, as judged by the sulphydryl test, and no more than dilute acids. Neutral urea solutions permit a study of the physical properties of glutenin without previous exposure to extremes of hydrogen ion concentration. This method should be applicable to the isolation of glutenins from other seeds.

scholarly journals THE VIABILITY OF HEMOLYTIC STREPTOCOCCUS IN CERTAIN SOLUTIONS CONTAINING GELATIN

1924 ◽  
Vol 39 (6) ◽  
pp. 811-825 ◽  
Author(s):  
Frank L. Meleney ◽  
Zung-Dau Zau
Keyword(s):  
Room Temperature ◽  
Mechanical Injury ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Hemolytic Streptococcus ◽  
Lytic Action ◽  
Cent Concentration ◽  
Actual Growth ◽  
Wide Zone

1. The findings of Robertson, Sia, and Woo with regard to the preservative action of 0.1 per cent gelatin in suspending fluids for the pneumococcus have been confirmed for the streptococcus. 2. In gelatin-citrate, gelatin-Locke's, and gelatin-"20:1" solutions, the streptococcus will live for 3 days or longer at room temperature and for 12 hours or longer at incubator temperature in dilutions as high as 100 cocci per cc. 3. The gelatin in 0.1 per cent concentration maintains life at a fairly constant numerical level for from 15 to 24 hours. These fluids may therefore be used for certain quantitative biologic tests. 4. In slightly higher concentrations of gelatin, there is actual growth which suggests that even in 0.1 per cent concentrations the gelatin has a nutrient action. 5. There is also evidence that gelatin affords some protection against the mechanical injury of the dilution process. 6. The toxic action of unbalanced salts, the possible lytic action of water, and the autolytic action of the organisms themselves are all delayed by the presence of gelatin, but eventually these actions take place in the same manner that has been described before by many observers and as here observed for solutions without gelatin. 7. The life of streptococci is maintained in these gelatin solutions through a relatively wide zone of hydrogen ion concentration.

CONTRIBUTION TO THE STUDY OF THE PRECIPITATION OF CARBONATES, BORATES, SILICATES AND ARSENATES

1941 ◽  
Vol 19b (8) ◽  
pp. 179-204 ◽  
Author(s):  
Paul E. Gagnon ◽  
Louis Cloutier ◽  
R. Martineau
Keyword(s):  
Liquid Medium ◽  
Room Temperature ◽  
The Other ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Molar Ratio ◽  
Hydrogen Ion Concentration ◽  
Basic Carbonate ◽  
Series Of Experiments ◽  
Cobalt And Nickel

A study was made of the precipitation, at room temperature, of the carbonates of cadmium, cobalt, and nickel, of the chromate of beryllium, of the borates of zinc, of the silicates of copper and of the arsenates of lead. A rapid-mixing apparatus that insured that the precipitations took place in homogeneous liquid medium was used. In each series of experiments, the concentration of one reacting solution was kept constant and that of the other systematically varied. The values of the molar ratio of oxides, CdO/CO2 for example, in the precipitates were found by analysis. If they remained constant with different concentrations of reactants, a definite compound was indicated. The normal cadmium carbonate was obtained. Three definite basic compounds, not described in the literature, were prepared: a definite basic carbonate of cobalt, 5CoCO3∙Co(OH)2, and two definite basic arsenates of lead, 4Pb3(AsO4)2∙Pb(OH)2 and 9Pb3(AsO4)2∙Pb(OH)2. Dilead arsenate, PbHAsO4, was easily precipitated, but trilead arsenate, Pb3(AsO4)2, only under very specific conditions. The other precipitates were all mixtures. The influence of the hydrogen ion concentration of the solutions on the composition of the precipitates formed was determined.

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