Goward C R, Stevens G B, Hammond P M, Scawen M D
Division of Biotechnology, PHLS, Centre for Applied Microbiology and Research, Salisbury, Wiltshire, U.K.
J Chromatogr. 1988 Dec 21;457:317-24. doi: 10.1016/s0021-9673(01)82079-3.
Homogeneous beta-lactamase (beta-lactam hydrolase, E.C. 3.5.2.6) from Enterobacter cloacae P99, an enzyme that has an important function in antibiotic resistance, was prepared using a single cation-exchange chromatographic step with CM-Sepharose fast-flow. A 6-g amount of the enzyme was isolated from 5 kg of cell paste, with 84% of the enzyme activity in the cell homogenate being recovered by the single cation-exchange step. The specific activity of the beta-lactamase was 587 U/mg protein. The relative molecular mass of the enzyme was determined to be 45 kDa by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate and the isoelectric point was 8.95.
阴沟肠杆菌P99产生的均一β-内酰胺酶（β-内酰胺水解酶，E.C. 3.5.2.6）是一种在抗生素耐药性中起重要作用的酶，通过使用CM-琼脂糖快速流动的单一阳离子交换色谱步骤制备。从5千克细胞糊中分离出6克该酶，通过单一阳离子交换步骤回收了细胞匀浆中84%的酶活性。β-内酰胺酶的比活性为587 U/mg蛋白质。在十二烷基硫酸钠存在下通过聚丙烯酰胺凝胶电泳测定该酶的相对分子质量为45 kDa，其等电点为8.95。
