Abstract
1. L-Histidine deaminase was isolated from guinea pig liver and purified about forty folds.
2. This enzyme was strongly inhibited by metal- and SH-binders.
3. The enzyme inactivated through dialysis restored its activity by supplementing cadmium ion together with a SH-compound such as -GSH, thioglycollate or cysteine.
4. pH optimum of the enzyme was found at 8.7 and Km of the enzymatic reaction was about 1.2×10-3 mole/lit.
