Abstract
1. Partially purified preparation of the saccharogenic amylase of Aspergillus oryzae was isolated from Takadiastase. The principle of the method: Takadiastase solution is saturated completely with ammonium sulfate ahd the dialyzed supernatant is attacked with 1_??_2% HgCl2 at 30° for one or two days. Other enzymes are destroyed completely and only the saccharogenic enzyme remains.
2. The followings are some properties observed on the preparation:
(1) The saccharogenic activity is always associated with maltase activity and these are not separated each other by any methods so far tested.
(2) Optimum pH: 4.2_??_5.2 (Fig. 1, Part 2).
(3) Optimum temperature: 50_??_55° (Fig. 2, Part 2).
(4) Stable between pH 3.8_??_6.5, most stable at pH 5.2 (Table 1, Part 2). It is destroyed completely at that pH within 10 minutes at 70° Calcium ions appear to have an unfavourable influence upon the stability. (Table 2, Part 2)
(5) All of the following substances have no inhibitive or activating actions: HgCl2, CuSO4, Pb(CH3COO)2, FeSO4, AgNO3, ZnSO4, MgSO4, MnSO4, CaCl2, BaCl2, NaCl, NaF, KCl, KCN, phenol, streptomycin, chloromycetin, phenylhydrazine.
(6) The enzyme is not precipitated by trichloroacetic acid, phosphomolybdic acid, phosphotungstic acid, picric acid and tannic acid.
(7) 70_??_80% of its activity remains in the supernatant when the enzyme solution is saturated with ammonium sulfate. (Table 3, Part 2)
(8) Molecular weight: 7500_??_8000 by Northrop-Anson's diffusion method.
(9) Electrophoresis shows that the preparation yet contains two components (Photo 1, Part 1), perhaps the one may be a polysaccharide composed of glucose and xylose and the other may be a polypeptide containing tryptophan, arginine, isoleucine, valine, glutamic acid, lysine and one more that is not yet certained.
(10) Maximum absorption is at 278 mμ by Beckman Spectrophotometer. (Fig. 3, Part 2)
3. As it is shown above, the enzyme is not prepared in a pure state yet. However, these properties suggest us that the enzyme may be a very different one from other enzymes so far reported on its action and chemical compositions.
Further purification is following now.
