PROPERTIES OF AMP DEAMINASE FROM SKELETAL-MUSCLE OF SNAPPER

Several properties of AMP deaminase (EC 3.5.4.6) purified from the skeletal muscle of the snapper Pagrus auratus were investigated. The purified enzyme showed optimum activity at pH 7.2 in potassium phosphate buffer, and the activity was stable between pH 6.8-7.5. The purified enzyme was specific for 5'-AMP and a Michaelis constant for AMP in sodium cacodylate buffer at pH 7.2 was estimated at 1.6 mM when the activity was assayed in the presence of KCl. The enzyme was activated by monovalent cations: K+ was the most effective, followed by Na+, Li+, Rb+, and Cs+ in that order. It was markedly inhibited by Cd2+, Cu2+, and Zn2+. Fluoride exerted non-competitive inhibition on the enzyme with a Ki of 2.8 MM.