Characterization of an Aspergillus oryzae cysteinyl dipeptidase expressed in Escherichia coli.

Ryota Hattori1, Mayumi Matsusita-Morita1, Sawaki Tada1, Junichiro Marui1, Ikuyo Furukawa1, Satoshi Suzuki1, Hitoshi Amano2, Hiroki Ishida3, Youhei Yamagata4, Michio Takeuchi4, Ken-Ichi Kusumoto1

Author address: 

1National Food Research Institute, Ibaraki, Japan, 2Amano Enzyme Inc., Gifu, Japan, 3Gekkeikan Sake Company Ltd., Kyoto, Japan, 4Tokyo University of Agriculture and Technology, Tokyo, Japan.


Cysteinyl dipeptidase from A. oryzae (CdpA) was produced in Escherichia coli and purified. CdpA formed a homodimer and its molecular mass was determined as 109 kDa. CdpA-specific activity to Cys-Gly was 3.04 U/mg. The enzyme showed maximum hydrolyzing activity toward Ala-Cys, followed by Leu-Cys, Cys-Gly, Cys-Ala, and Gly-Cys among the cysteine-containing dipeptide substrates. Its substrate specificity was distinct from those of other cysteinyl dipeptidases of the M20 family. The activity of CdpA was increased by addition of Mn2+, Zn2+, and Co2+ at 0.1 mM. The activity was inhibited in the presence of Fe2+. Several protease inhibitors reduced the activity. The complete inhibition of enzyme activity by EDTA indicates that CdpA is a metallopeptidase. It was optimally active at pH 7-8 and stable at pH 6-9 and at up to 40 "¢Å½. This study was supported by the Program for Promotion of Basic Research Activities for Innovative Biosciences (PROBRAIN).

abstract No: 


Full conference title: 

26th Fungal Genetics Conference
    • Fungal Genetics Conference 26th (2005)