Abstract
Thiaminase II (Thiamin hydrolase) of Bacillus aneurinolyticus was purified to homogeneity. The enzyme activity was spectrophotometrically determined by measuring the rate of decrease in absorbance at 318 nm. The optimum pH and temperature were 9.4 and 65℃, respectively. Apparent activation energy was calculated to be 16.1 kcal/M from Arrhenius plots, and the Km value was 8.4 μM. Some sulfhydryl reagents enhanced the enzyme activity by 180-300%, while EDTA had no effect. Zn^lt:2+> among metal ions tested strongly inhibited the enzyme activity.
