A Streptomyces spp. strain SY 79-1 which was capable of producing metal protease was isolated from soil. The optimal pH and temperature of the protease were around pH 8.0 and 45℃, respectively. The stable pH range of the enzyme was between pH 6.0 to 8.0. The enzyme was stable at 45℃, but it lost the activity about 75 % for 5 min and completely for 30 min when it was treated at 60℃. The activity of the enzyme was inhibited by Hg^(++), Cu^(++), Ag^+ and activated by Mg^(++), Mn^(++), Co^(++), but Fe^(++), Ca^(++), Pb^(++) and Al^(3+) did not affect enzyme activity.
This enzyme was strongly inhibited by EDTA, but was not inhibited by 2, 4-DNP, p-CMB, ε-aminocaproic acid, cysteine, thiourea, citric acid, oxalic acid and sodium arsenate. When cobalt was added to the EDTA-denatured enzyme, the activity of the enzyme was restored.
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