Studies on the Salivary Gland Hormones. XIV

Isolation of Crystalline Parotin by Fractional Precipitation with Ammonium Sulfate

抄録

When the pH 5.4-precipitate is purified by means of fractional precipitation with ammonium sulfate, an effective protein substance is obtained in crystalline state from the fraction precipitating at 12.1% concentration of ammonium sulfate. This substance was found to be approximately 90% pure by electrophoretic analysis. Its behavior towards sodium and ammonium sulfate is similar to that of γ-globulin but its mobility in electrophoresis give values intermediate of albumin and α-globulin of human serum, and much nearer that of α-globulin. The dialyzate of the crystals, when injected intravenously to rabbit at the rate of 1mg. per 2kg. body weight (calculated from evaporation residue), showed the decrease of 14.41% rate in serum calcium. Fractional precipitation with sodium sulfate alone gave amorphous precipitate but subsequent fractional precipitation with ammonium sulfate gave crystalline product. The fraction of total ammonium sulfate-saturation, compared to the crystalline portion, showed weak potency with strong toxicity. This toxicity could not be removed by dialysis.