Abstract:

Cysteine protease from Zea mays (zmCP1) was cloned by PCR with corn genome DNA as template, and ligated to pET28a(+), expressed in E.coli BL21(DE3). The recombinant enzyme was identified by SDSPAGE and Western blotting, finally purified through Nichelating affinity chromatography. The purity can reach 95%. The properties characterization of zmCP1 showed that the optimal temperature was 55 ℃, and the optimal pH was 6.0, the halftime was 39.82 min at 90 ℃. The enzyme kinetics researches with RAMC and LAFR-AMC as substrate show that zmCP1 has better affinity and catalytic activity to small substrate.

Key words: Zea mays, cysteine protease, prokaryotic expression, enzyme properties