Characteristics of a alkaline protease from Alteromonas sp.

Alteromonas sp.가 생산하는 alkaline protease의 특성

An alkaline protease-producing bacterium was isolated from Korean hot pepper paste and identified as Alteromonas sp. CN301. A alkaline protease was purified and characterized. The optimal pH and temperature for the enzyme activity were pH 12.0 and $35^{\circ}C$, respectively. Molecular weight of the enzyme was determined as 31,000 dalton by the SDS-PAGE. The enzyme was stable in the range of $pH\;6.0{\sim}13.0$ showing the residual activity above 80% of the enzyme activity. The residual activity of the enzyme was 64% when the enzyme was incubated at $50^{\circ}C$ for 1 hr. The activity of the enzyme was not affected by most metal ions tested except $Hg^{2+}$, and activated by Triton X-100, Tween 20 and Tween 80. The enzyme activity was severely inhibited by PMSF and EDTA, suggesting that the enzyme is serine protease having metal ion in its structure.

알칼리성 protease를 생산하는 균을 고추장에서 분리하여 Alteromonas sp. CN301로 동정하고 그 알칼리성 protease를 생산하여 정제효소의 성질을 조사한 결과, 최적 pH 12.0, 최적 온도 $35^{\circ}C$이었으며 pH 안정성은 $pH\;6.0{\sim}13.0$ 범위에서 80% 이상의 잔존효소 활성을 나타냈고 $50^{\circ}C$에서 1시간 처리로 64%의 활성을 보였다. SDS-PAGE에 의한 분자량은 31,000 dalton이었고 $Hg^{2+}$를 제외한 다른 금속이온에 대해서는 저해를 받지 않았다. 계면활성제인 Triton X-100, Tween 20과 80은 이 효소의 활성을 상승시키는 효과를 보였으며 EDTA와 PMSF에 의하여 효소활성이 저해되므로 효소분자 중에 금속이온을 가지는 serine protease로 생각되었다.