Properties of
Recombinant Aeromonas punctata Prolyl
Endopeptidase
LI Min, SHEN Guo-Xiang and CHEN Chang-Qing
( Shanghai Research Center of Biotechnology, Chinese Academy of Sciences,
Shanghai 200233, China )
WANG De-Bao
( State Key Laboratory of Molecular Biology, Shanghai Institute of
Biochemsitry, Chinese Academy of Sciences, Shanghai 200031, China
)
Abstract 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 ℃ and 8.4,
the stability of the apPEP was in the range of 4-32 ℃ and pH 6.0-10.0, and its Km
was 0.03 mmol/L based on the Z-Gly-Pro-βNA. The apPEP was not sensitive to PMSF,
TLCK, TPCK, Trypsion inhibitor, EDTA, tetrathionate and some metal ions, but
was sensitive to SDS and Zn2＋, 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-βNA.
Key Words Aeromonas punctata； recombinant prolyl
endopeptidase； enzymatic property
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