青霉素酶分离纯化及酶学性质研究

Purification and characterization of penicillinase

本文对蜡状芽孢杆菌CMCC(B)63301产青霉素酶的分离纯化工艺及酶学性质进行了研究。粗酶液通过硫酸铵分级盐析、超滤除盐浓缩、SephadexG-75凝胶层析纯化后得到的青霉素酶液的比活力为68.2×106u/mg,纯化倍数为11.32,酶活回收率为35.04%。经SDS-PAGE检测为单一区带。该酶作用的最适温度为37℃,最适作用pH范围为6.5～7.0,在0～20℃下存放比较稳定。酶液中添加5%NaCl或5%甘油可提高酶的保存稳定性。

In this study, purification and characterization of penicillinase produced by Bacillus cereus CMCC（B） 63301 were investigated. The crude enzyme was purified through following steps： ammonium sulfate precipitation; concentration and Sephadex G-75 gel filtration. The purified enzyme showed a single band on SDS polyacrylamide gel electrophoresis with a purification of 11.32 folds and a yield of 35.04%. The optimal reaction conditions for the enzyme were pH 6.5-7.0 at 37℃. The enzyme was stable at the normal temperature and was not stable at higher temperature, increasing 5 % NaCl or 5% glycerin can prolong the storing time and increasing the stability of the penicillinase.