Properties of Recombinant Aeromonas punctata Prolyl Endopeptidase.
The properties of recombinant Aeromonas punctata prolyl endopeptidase(apPEP) were studied using specific substrate and peptides. Results show that the optimum catalytic temperature and pH was 34 degrees and 8.4, the stability of the apPEP was in the range of 4-32 degrees and pH 6.0-10.0, and its K(m) was 0.03 mmol/L based on the Z-Gly-Pro-betaNA. The apPEP was not sensitive to PMSF, TLCK, TPCK, Trypsion inhibitor, EDTA, tetrathionate and some metal ions, but was sensitive to SDS and Zn(2 ), and was completely inhibited by DFP. Oxytocin and calcitonin could be specifically hydrolyzed by apPEP at the carboxyl site of proline residue, but the hydrolysis efficiency of calcitonin by the enzyme was less than for oxytocin and for Z-Gly-Pro-betaNA.
Li
Min
M
Shanghai Research Center of Biotechnology, Chinese Academy of Sciences, Shanghai 200233, China. limin@server.shcnc.ac.cn
Shen
Guo-Xiang
GX
Chen
Chang-Qing
CQ
Wang
De-Bao
DB