液化沙雷菌超广谱β-内酰胺酶的特性研究  

Study on characteristics of extended spectrum β-lactamases from Serratia liquefaciens

作　　者：李苌清[1] 凌保东[1] 周歧新[2] 雷军[1] 余娴[1] 

机构地区：[1]川北医学院药物研究所,南充637007 [2]重庆医科大学药理教研室,重庆400016

出　　处：《中国抗生素杂志》2005年第9期552-554,共3页Chinese Journal of Antibiotics

基　　金：四川省重点科技攻关项目(编号02SG022-030)

摘　　要：目的研究液化沙雷菌超广谱β-内酰胺酶的特性。方法超声破碎法提取临床分离液化沙雷菌CR 04的β-内酰胺酶,等电聚焦(IEF)测定其等电点(pI);硫酸铵反抽提、Sephadex G-75凝胶过滤和DE-52阴离子交换层析进行酶的纯化;SDS-PAGE法测定分子量和紫外分光光度法测定酶动力学参数。结果液化沙雷菌超广谱β-内酰胺酶的pI为7.5,分子量为28.77ku,动力学分析显示,该酶能水解头孢他啶、头孢噻肟和氨曲南,对舒巴坦(IC50为77nm o l/L)和三唑巴坦(IC50为17nm o l/L)敏感。结论液化沙雷菌产生的超广谱β-内酰胺酶对酶抑制剂敏感。Objective To study characteristics of extended spectrum β-lactamase from Serratia liquefaciens CR04. Methods Crude β-lactamase was extracted by sonication and isoelectric point of β-lactamase was determinded by IEF;β-lactamase was purified by ammonium sulfate precipitation, DE-52 ion-exchange chromatography and gel filtration on Sephadex G-75. Molecular weight was detected by SDS-PAGE and kinetic parameters for β-lactamas were detected spectrophotometrically. Results The β-lactamase has a pI value of 7.5 and its molecular weight is 28.77ku. Kinetic studies of partially purified β-lactamase confirmed that the enzyme was able to hydrolyse ceftazidime, cefotaxime and aztreonam. The β-lactamase activity was well inhib- ited by tazobactam （IC50= 17nmol/L） and sulbactam （IC50=77nmol/L）. Conclusion The extended spectrum β-lactamase produced in Serratia liquefaciens CR04 was sensitive to enzyme inhibitor.

关 键 词：头孢他啶 超广谱Β-内酰胺酶 液化沙雷菌 

分 类 号：R378[医药卫生—病原生物学]