In this study, some kinetic properties of arginase in bovine spleen tissue were examined.

The spleen tissues used in the present study were obtained from the Elkas sloughterhause in Elazıg. The thiosemicarbazide- diacetylmonoxime urea (TDMU) method was used

Preincubation temperature, preincubation period, incubation period and optimal pH were determined to be 62ºC, 15 min, 10 min and 9.7 respectively. Furthermore, it was found that arginase in bovine spleen tissue was sensitive to different metal ions. It was found that the most effective was Mn⁺² from among Mn⁺², Cu⁺², Mg⁺², Ba⁺², Fe⁺³, Ag⁺², Cr⁺³, Sn⁺², Hg⁺², Pb⁺², Co⁺², Ni⁺², Zn⁺², Cd⁺², Li⁺¹, K⁺¹, Al⁺³, Mo⁺⁶, Na⁺¹ and Ca⁺² metal ions. Arginase showed the

highest activity in a 2 mM MnCl₂ concentration. Manganese ions and preincubation were necessary for the activation of the enzyme. The enzyme has no activity in presence of Pb and Ag ions.

The relationship with the enzyme substrate was evaluated according to Michaelis- Menten and the Km value was 5 mM.