Abstract
The angiotensin I converting enzyme (ACE) has an important role in the maintenance of blood pressure. The ACE inhibitory activities of foods have recently been studied. We tried to isolate ACE inhibitory peptides from the Flavourzyme (FZ), Pescalase (PE), and Thermolysine (TH) protease digests of corn gluten, which was restricted to the use the source of food for digestion problem. The FZ, PE, TH/PE protease hydrolyzed corn gluten and the inhibitory activities of the hydrolyzates for ACE were measured. Major fractions were isolated from the digests using ODS chromatography after treating with ethanol in step gradient. The ACE inhibitors were further purified by Bio-Gel P-2 column and reverse phase HPLC. Five inhibitory peptides were isolated. Their amino acids were sequenced as LPF ($IC_{50}$ = 40$\mu$M), GPP ($IC_{50}$ = 17.6$\mu$M), PNPY ($IC_{50}$ = 30.7$\mu$M), SPPPFYL ($IC_{50}$ = 63 $\mu$M), and SQPP ($IC_{50}$ = 17.2$\mu$M).
안정성이 확보된 식품에서 ACE저해 활성 물질을 검색하는 연구의 일환으로, 옥수수 글루텐을 Flavourzyme, Pescalase, 그리고 Thermolysine/Pescalase 등으로 가수분해하여 얻은 가수 분해물로부터 ACE 활성 저해 펩타이드를 다음과 같은 과정으로 분리, 정제하였다. 10% 에탄올로 평형화된 ODS chromatography를 이용 단백질 분획들을 얻고, Bio-Gel P-2 column과 reverse phase HPLC를 통해 5개의 ACE 저해 펩타이드를 분리, 정제하였다. 그 아미노산 서열은 LPF($IC_{50}$ = 40 $\mu$M), GPP($IC_{50}$ = 17.6 $\mu$M), PNPY($IC_{50}$ = 30.7 $\mu$M), SPPPFYL($IC_{50}$/ = 63 $\mu$M), and SQPP($IC_{50}$ = 17.2 $\mu$M)로 밝혀졌다. 이 펩타이드들은 경구투석 시 가수분해 효소에 대응하여 체내에서 안정성이 뛰어나고, 소장에서도 쉽게 흡수될 것으로 사료되어 상시 섭취하는 식품이나 음료에 첨가하여 이용한다면 그 유용성이 기대된다.
