摘要
应用溶菌酶溶菌、硫酸铵沉淀蛋白质及新生霉素琼脂糖ＣＬ－６Ｂ相结合的方法，成功地从大肠杆菌ＫＬ－１６分离到ＤＮＡ旋转酶的Ａ、Ｂ亚单位。单独的Ａ、Ｂ亚单位均无ＤＮＡ旋转酶活性，以Ａ、Ｂ亚单位重组的酶能将松弛的质粒（ｐＢＲ３２２）ＤＮＡ转变为超旋型。各种喹诺酮类药物均对其活性具有抑制作用。萘啶酸、诺氟沙星、氧氟沙星、司帕沙星、环丙沙星及ＤＵ－６８５９抑制该酶活性６０％所需浓度（ＩＣ＿（５０））分别为６７．４９、１．８８４、１．３７５、０．６１３、０．３６１和０．１７８μｇ／ｍｅ。各药物ＩＣ５０与其最低抑菌浓度（ＭＩＣ）平行。
Subunit A and subunit B proteins of DNA gyrase fromEscherichia coli KL-16 were successfully isolated and purified by the co-mbined method of bacterial lysis using lysozyme, protein precipitation w-ith ammonium sulfate and affinity chromatography on Novobiocin Seohar-ose CL-6B.Both uncoupled subunit A and subunit B had no enzvmatic a-ctivities, but the reconstituent holoenzvme with subunit A and B couldconvert the relaxed plasmid pBR322 DNA into supercoiled form.Quinolo-nes could inhibit the supercoiling activity of DNA gyrase. The 50%inh-ibitory conentration(IC_(50))of Nalidixlc acid,Norfloxacin’Ofloxacin,Sp-arfloxacin,Ciprofloxacin and DU-6859 were 67.49,1.884,1.375,0.613,0.361 and 0.178μg/ml respectively.The IC_(50)s of quinolones were correl-ated with their MICs.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
1994年第1期46-48,共3页
Chinese Journal of Antibiotics
