| 摘要 |
The invention provides purified PNB esterase from a microorganism of the genus Bacillus. The enzyme is a monomer having a molecular weight of about 54,000 daltons. This PNB esterase catalyzes the deesterification of PNB-esters of cephalosporin and 1-carbacephalosporin compounds to the free acid form. The invention also provides a process for purifying the enzyme from a Bacillus species. This process comprises a combination of ammonium sulfate fractionation, pH treatment, anion-exchange chromatography, gel filtration, adsorption-desorption chromatography, and affinity chromatography. |
