Streptomyces rimosus가 생산하는 Protease의 정제와 특성

Purification and Properties of Extracellular Protease from Streptomyces rimosus

Oxytetracycline 생산균주인 Streptomyces rimosus를 maltose 2%, NH$_4$Cl 0.5%, yeast extract 0.4 %, MGSO$_4$.7$H_2O$ 0.2% 조성의 배지를 배양초기 PH 6.5로 하여 3$0^{\circ}C$, 72시간 진탕배양하여 얻은, 세포외 protease를 유안분획, Sephadex A-50 이온교환, Sephadex G-100 gel 여과를 행하여 정제하였다. 효소의 최적온도는 5$0^{\circ}C$이며, 최적 pH는 8.0이었으며, Co$^{2+}$ 이온에 의해 활성화되며 Hg$^{2+}$, Fe$^{2+}$ 및 EDTA에 의해 저해를 받으며 casein 분자량을 23,600으로 추정하여 구한 Km값은 2.7$\times$$10^{-4}$M이었다.

Extracellular neutral pretense of Streptomyces rimosus producing oxytetracycline was purified by ammonium sulfate fractionation, DEAE Sephadex A-50 chromatography and Sephadex G-100 gel filteration, and was showed single band on the cathodic gel electrophoresis. The optimum pH and temperature of the enzyme were pH 8.0 and 6$0^{\circ}C$, respectively. The enzyme was activated about 80% in the presence of Co$^{2+}$ ion, and strongly inhibited by Hg$^{2+}$, Fe$^{2+}$ and chelatig agent, EDTA. Molecular weight of the enzyme was estimated to be 12, 000. The Km value of the enzyme of casein as a substrate was 2.7$\times$10$^{-4}$M.