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 pGAPZαC 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 μM. A 128-fold increase of ACEI activity (0.69 μM) was obtained after pepsin digestion, which was equivalent to 0.022 μM of captopril. Reverse phase HPLC indicated all the 8 peptides contained in ACEI-hydrolysate after pepsin digestion.

中文翻译：

---

利用巴斯德毕赤酵母表达系统生产对血管紧张素I-转化酶具有抑制能力的功能性肽

为获得血管紧张素-I转化酶抑制剂（ACEI），将编码GPL、GPM、IKW、IVY、IRPVQ、IWHHT、IYPRY和IAPG 8条DNA序列的融合ACEI多肽经筛选设计克隆到pGAPZαC中，然后转化为毕赤酵母SMD1168H。诱导 3 天后，使用 Ni Sepharose™ 6 Fast Flow 表达和纯化 ACEI 活性最高的部分。重组ACEI多肽的IC50为88.2 μM。胃蛋白酶消化后，ACEI 活性增加了 128 倍（0.69 μM），相当于 0.022 μM 的卡托普利。反相 HPLC 表明胃蛋白酶消化后 ACEI 水解物中包含的所有 8 种肽。