Abstract: Cysteine protease from Zea mays (zmCP1) is a proteolytic enzyme that, as a member of the C1 protease family,
can be widely used in the food and medicine industry. In this study, the total RNA of Zea mays was extracted from its
seedlings, zmCP1 was cloned by reverse transcription-polymerase chain reaction (RT-PCR), and then the recombinant
eukaryotic expression vector pPICZα-zmCP1 was constructed and transformed into P. pastoris GS 115. The optimal
temperature and pH for the expressed enzyme zmCP1 were 55 ℃ and 6.0, respectively, and it possessed good thermal
stability and high organic solvent tolerance. But it had medium pH stability and metal ion tolerance. Substrate specificity
analysis showed that the enzyme had strong hydrolysis ability for small molecules and preferred to hydrolyze substrates with
Arg residue at the P1 site.

Key words: cysteine protease from Zea mays, eukaryotic expression, enzymatic properties