抄録
We obtained the thiaminase II in crude state from synthetic culture filtrate of Bacillus aneurinolyticus Kimura et Aoyama by ammonium sulfate separation, and prepared from it resin treated enzymes, viz. K-enzyme was treated by cation exchanger, Amberlite IR-120,A-enzyme was treated by anion exchanger IRA-400,and R-enzyme was treated by both anion and cation exchangers. These preparations were compared with one another on their enzymatic activity, especially on the influences of metallic ions and chelating agents, and the following results were obtained : (1) Metallic ions (except Cd^‥) hardly inhibited the activity of the crude enzyme and A-enzyme, but activated K-enzyme in a small degree. (2) Cd^‥ remarkably inhibited the activity of all of these enzymes. (3) Chelating agents (except α, α'-dipyridyl) remarkably activated every resin-treated enzymes, such as K-, A- and R-enzyme, but hardly effected on the crude enzyme. Above all, EDTA was conspicuous activator. (4) α, α'-Dipyridyl was a strong inhibitor against all thiaminase II mentioned above. (5) The activating effects of EDTA was observed in the case of existence of same molar metallic ions as EDTA concentration, and this effect was lost by metallic ions 100 times as many as EDTA.
