토양에서 분리(分離)한 Streptomyces 속 중(中) 금속을 함유하는 푸로테아제를 강(强)하게 분비하는 균주 SY 79-1을 선별하여 그 효소학적 성질 몇가지를 조사해 본 결과는 다음과 같다. 1. 본 효소의 최적 pH는 8.0 부근이며 최적 온도는 $45^{circ}C$였다. 2. 본 효소는 중성(中性) 부근(附近)에서는 비교적 안정하며 열처리에 대해서는 $45^{circ}C$에서는 안정했으나 $60^{circ}C$에서는 5분간 처리로 약 70%, 30분간 처리로 완전(完全)히 실활(失活)하였다. $Hg^{++},;Ag^{+}Cu^{++}$ 등(等)에 의(依)해서 강하게 저해(沮害)되고, $Mg^{++},;Mn^{++},;Co^{++}$ 등(等)은 효소 활성을 증진 시켰으며, $Fe^{++},;Ca^{++},;Pb^{++},;Al^{++} 등(等)에는 별 영향을 받지 않았다. 4. 각종 저해제 중(中) EDTA에 의해서는 강하게 저해 되었으나, 2,4-DNP, ${ ho}$-CMB, ${varepsilon}$-aminocaproic acid thiourea, Na-arsenate, cysteine, oxalate, 구연산에 의해서는 영향을 받지 않았으며, EDTA에 의해서 저해(沮害)된 산소(酸素) 활성(活性)은 $Co_{++}$에 의해서 부활되었다.
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 $45^{circ}C$, respectively. The stable pH range of the enzyme was between pH 6.0 to 8.0. The enzyme was stable at $45^{circ}C$, but it lost the activity about 75 % for 5 min and completely for 30 min when it was treated at $60^{circ}C$. 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, ${ ho}$-CMB, ${varepsilon}$-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.
