摘要
经过硫酸铵30%~50%分级沉淀、二步柱层析可获聚丙烯酰胺凝胶电泳均一的粘质赛氏菌胞外蛋白酶制品,收率可达53%,并制备了酶的结晶,该酶以SephadexG100柱层析及SDS-PAGE测得分子量约为81000,该酶的最适pH为7.0,最适温度为45℃,Zn2+、Mn2+、Fe2+、Cu2+、Co2+等重金属离子不同程度地抑制酶活性。
The extracellular proteinase from Serralia Marcescens 41003(2) has been purified by a series methods including:(NH4)2SO4 fractional salting out(30%-50%),Sephadex G-100 chromatography and DEAE-Cellulose 32 chromatography.The purified proteinase was about 46-fold purity of the culture supernatant by enzyme assay.It was found to be hornogeneous as judged by PAGE.The purified proteinase showes approximate molecular weight of 81 000 by Sephadex G-100 chromatography.The proteinase exhibits an optimum pH about 7.0 for casein digestion and optimum temperature at 45℃.Its activity is stable below 45℃.and can be inhibited by Zn2+.Mn2+,Fe2+,Cu2+ and Co2+.The rod shape crystalls of the proteinase have been obtained from ammonium sulfate solution.
关键词
细菌
粘质赛氏菌
胞外蛋白酶
分离
性质
分离
Serratia Marcescens 41003(2).Extracellular proteinase,Isolation and purification,Crystal of the proteinase,Characterization