【摘要】 以Bacillus Sphaericus 78为材料,经亲和层析——高效液相色潜,分离纯化制得电泳纯的限制性核酸内切酶Bsp78I,得率为2020units/g湿菌。所纯化的酶经SDS—PAGE分析为一条带,并测得酶亚基分子量为72 000;经Sephadex G—200凝胶层析测得酶分子量为141 250,说明该酶由两个相同的亚基组成。用Edman降解法和HPLC ULTRASPHERE—PTH柱层析测得Bsp78I酶N—末端氨基酸残基是色氨酸。更多还原

【Abstract】 Restriction endonuclease Bsp78 Ⅰ（Ⅰ） was purified to homogeneity from Bacillus Sphaericus 78 by using affinity chromatography and HPLC （Heparin—Sepharose, HPLC TSK 3000sw, Cibacron Blue F₃GA—Sepharose and HPLC TSK 3000sw, column again）. The yield of purified enzyme （Ⅰ） was 2020 units/g wet bacteria （Ⅰ） exhibits a single band of 72 000dr on SDS—PAGE. （Ⅰ） has a molecular weight of 141250dt by Sephadx G—200 gel filtration The results shows that（Ⅰ）consists of two similar subunits. The results of Edman degradation and HPLC ULTRSPHERE—PTH column chromatography shows that the N—terminal amino acid residue of （Ⅰ） was Tryptophan更多还原