Production of functional peptides with inhibition ability against angiotensin I-Converting enzyme using P. pastoris expression system

Hsueh-Ming Tai ^a, Ching-Chin Li ^a, Chun-Yu Hung ^a, Li-Jung Yin ^b,*

^a Nugen Bioscience (Taiwan) Co., Ltd, 4F., No.35, Keya Rd., Daya Dist., Taichung City, 428, Taiwan

^b Department of Seafood Science, National Kaohsiung University of Science and Technology, No.142 Hai-Chuan Rd. Nan-Tzu, Kaohsiung, 81143, Taiwan

To obtain the angiotension-I converting enzyme inhibitor (ACEI), a fusion ACEI polypeptide encoded with 8 DNA sequences of GPL, GPM, IKW, IVY, IRPVQ, IWHHT, IYPRY and IAPG, which were selected and designed and cloned into pGAPZaC and then transformed into Pichia pastoris SMD1168H. After 3 days induction, the fraction with highest ACEI activity was expressed and purified using a Ni Sepharose™ 6 Fast Flow. The IC50 of recombinant ACEI polypeptide was 88.2 mM. A 128-fold increase of ACEI activity (0.69 mM) was obtained after pepsin digestion, which was equivalent to 0.022 mM of captopril. Reverse phase HPLC indicated all the 8 peptides contained in ACEI-hydrolysate after pepsin digestion.

Keywords: Angiotesin I-converting enzyme, inhibitory peptides, Cloning Expression