Biochemical characterization of an extracellular protease in Serratia proteamaculans isolated from a spider = 무당거미에서 분리한 Serratia proteamaculans에서 분비되는 단백질분해효소의 생화학적 특성

Abstract

Serratia proteamaculans isolated from the midgut of a spider formed big halos around the bacterial colonies, indicating that the bacterial strain produces an extracellular protease. Activity staining of the extracellular protein fractions using zymogram also demonstrated that the major protein with an estimated molecular mass of 52 kDa contained a high proteolytic activity. The protease was purified to near electrophoretic homogeneity from the culture supernatant after filtration and ion exchange and size exclusion chromatography. The purified enzyme had a relatively high proteolytic activity between pH 6.0 and 10.0 and at broad temperature range. The proteolytic activity of the enzyme was not inhibited by phenylmethylsulfonyl fluoride but strongly inhibited by 1, 10-phenanthroline and EDTA. The activity also was dependent on the presence of Ca++ and Zn++ ions. These observations indicate that the enzyme is a metalloprotease.