• 미생물학회지
• /
• 제39권4호
• /
• pp.230-234
• /
• 2003

Bacillus amyloliquefaciens psychrotrophic strain이 분비하는 세포 외 단백질 가수분해효소를 정제하여, endopeptidase 활성에 관한 특성을 분석하였다. Protease SE910로 명명된 효소는 단백질 내부의 leucine에 연결된 peptide 결합만을 가수분해하는 endopeptidase로 작용한다. 효소를 특이한 아미노산 잔기에 작용하는 화학수식제와 반응하였을 때 효소의 활성부위에 관여하는 아미노산 잔기가 수식되었을 때는 효소활성이 저해를 받는다. 본 효소는 serine을 수식하는 PMSF에의해 endopeptidase 활성이 완전히 저해되었으며, 카르복실 기능기를 수식하는 화학수식제에 의해 저해되었고, lysine을 화학수식하는 PLP에 의해서는 큰 영향을 받지 않았다. 이것은 본 효소의 endopeptidase 활성에 serine과 aspartic acid 잔기가 관여하는 것을 의미한다. 구조적으로 leucine을 포함하는 유도체인 bestatin은 효소의 endopeptidase 활성을 경쟁적으로 저해하였다.

• Journal of Microbiology
• /
• 제43권3호
• /
• pp.237-243
• /
• 2005

The protease purified from Bacillus cereus JH108 has the function of leucine specific endopeptidase. When measured by hydrolysis of synthetic substrate (N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide), the enzyme activity exhibited optimal activity at pH 9.0, $60^{\circ}C$. The endopeptidase activity was stimulated by $Ca^{++},\;Co^{++},\;Mn^{++},\;Mg^{++},\;and\;Ni^{++}$, and was inhibited by metal chelating agents such as EDTA, 1,10-phenanthroline, and EGTA. Addition of serine protease inhibitor, PMSF, resulted in the elimination of the activity. The endopeptidase activity was fully recovered from the inhibition of EDTA by the addition of 1 mM $Ca^{++}$, and was partially restored by $Co^{++}\;and\;Mn^{++}$, indicating that the enzyme was stabilized and activated by divalent cations and has a serine residue at the active site. Addition of $Ca^{++}$ increased the pH and heat stability of endopeptidase activity. These results show that endopeptidase requires calcium ions for activity and/or stability. A Lineweaver-Burk plot analysis indicated that the $K_m$ value of endopeptidase is 0.315 mM and $V_{max}$ is 0.222 ) is $0.222\;{\mu}mol$ of N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide per min. Bestatin was shown to act as a competitive inhibitor to the endopeptidase activity.

• 한국식품영양과학회지
• /
• 제32권7호
• /
• pp.971-975
• /
• 2003

우리나라가 고령화사회에서 고령사회로, 고령사회에서 초고령사회로 도달하는 시간이 각각 22년과 10년으로 추정되며 선진국에 비해 진입속도가 빠를 것으로 보고 있다. 고령화인구에 따라 일상생활은 물론 지역 사회에서의 활동, 더 나아가서는 직업 활동을 할 수 없는 기억 장애현상인 노인성 치매가 더욱 문제시된다. 따라서 본 연구에서는 우리나라에서 정신건강 관련하여 이미 이용되고 있거나 민간에서 구두로 알려진 식품 총 100종을 선정하고, 메탄올 추출물에 대하여 prolyl endopeptidase에 대한 활성 저해율을 측정하였다. 그 결과, 40ppm 농도에서 도토리가 96.0%로 가장 높은 활성 저해율을 보였고, 산딸기가 92.0%, 호두가 73.0%로 나타났으며, 그 외의 나머지 식품들은 56.1%인 녹차를 제외하고는 모두 50% 미만의 수준이었다. 본 연구결과 PEP에 비교적 특이적으로 작용하는 저해제로서 도토리와 산딸기를 확인할 수 있었고, 현재까지 개발되고 보고된 합성 peptide인 PEP저해제와는 달리 천연식품이란 점에서, 앞으로 이 식품들이 항치매 예방 기작 구명에 유용하게 이용됨과 동시에 치매의 예방을 위한 기능성 식품으로서 이용될 수 있을 것으로 기대된다.

• Applied Biological Chemistry
• /
• 제43권2호
• /
• pp.158-161
• /
• 2000

• Archives of Pharmacal Research
• /
• 제26권12호
• /
• pp.1024-1028
• /
• 2003

A prolyl endopeptidase inhibitor was isolated from the ethyl acetate soluble fraction of Phyllanthus ussurensis. The active compound was identified as an ellagitannin, corilagin. It was shown to non-competitively inhibit prolyl endopeptidase (PEP) with the $IC_{50}$ value of $1.17 \times $10^{-6}\mu$M. The Ki value was $6.70 \times 10^{-7}$ M. Corilagin was less inhibitory to other serine proteases such as chymotrypsin, trypsin, and elastase, indicating that it was relatively a specific inhibitor of PEP. Corilagin also effectively inhibited reactive oxygen species such as hydroxide and superoxide anion radical, hydrogen peroxide, and DPPH. Especially, corilagin showed potent scavel1ging activity on the superoxide anion radical in the ESR method ($IC_{50} =3.79 \times 10^{-6}$M) as well as xanthine oxidase system.

• 생약학회지
• /
• 제30권3호
• /
• pp.231-237
• /
• 1999

About forty sea weeds were screened for their inhibitory effects against prolyl endopeptidase, tyrosinase and thrombus coagulation. Out of them, methanolic extract of Ecklonia cava, Sargassum patens, Sargassum hemiphyllum, Sargassum thunbergii, Sargassum singgildianum, Hizikia fusiformis, and Ishige okamurae inhibited more than 90% of prolyl endopeptidase activity at 40 ppm. Sargassum siliquastrum and Ecklonia cava exhibited 51% and 76% of inhibitory activity against tyrosinase at 40 ppm, respectively. In APTT assay system, Sargassum singgildianum, Pterocladia capilacea and Hizikia fusiformis delayed coagulation of thrombus about two times (210, 211, and 198% over control at ca 367 ppm, respectively) and in TT assay, Lomentaria catenata, Laurencia okamurae, and Hizikia fusiformis did most effectively (216,197, and 251% at ca 367 ppm, respectively).

• Journal of Applied Biological Chemistry
• /
• 제56권3호
• /
• pp.183-185
• /
• 2013

Two styrylpyranones (1 and 2) were isolated from the $CH_2Cl_2$-soluble fraction of Phellinus linteus and their structures were established by extensive Nuclear magnetic resonance (NMR) spectral data as inoscavin E and C. Both compounds showed significant prolyl endopeptidase inhibitory activity with $IC_{50}$ values of $4.26{\pm}0.14$ and $4.08{\pm}0.04{\mu}M$ and $K_i$ values of $1.50{\pm}0.02$ and $1.43{\pm}0.03{\mu}M$, respectively. They also exhibited antioxidant capacities against the ABTS radical system with $EC_{50}$ values of $6.47{\pm}0.05$ and $7.64{\pm}0.06{\mu}M$, respectively.

• Journal of Applied Biological Chemistry
• /
• 제48권4호
• /
• pp.207-212
• /
• 2005

Prolyl endopeptidase (PEP, EC 3.4.21.26), also referred to as prolyl oligopeptidase, has been suggested to participate in learning and memory processes by cleaving peptide bonds on carboxyl side of prolyl residue within neuropeptides of less than 30 amino acids, and is abundant in brains of amnestic patients. Therefore, compounds possessing PEP inhibitory activity can be good candidate of drug against memory loss. Upon examination for PEP inhibition from traditional medicinal plants having tonic, stimulating, and anti-amnestic effects, Corni Fructus (Cornus officinallis) showed significant PEP inhibition. Ursolic and oleanolic acids, components of Corni Fructus, inhibited PEP with $IC_{50}$ values of $17.2\;{\pm}\;0.5$ and $22.5\;{\pm}\;0.7\;{\mu}M$, respectively.

• Archives of Pharmacal Research
• /
• 제21권2호
• /
• pp.207-211
• /
• 1998

Three prolyl endopeptidase inhibitors were isolated and identified as luteolin, quercetin and ${\beta}$-sitosterol-3-O-${\beta}$-D-glucopyranoside with $IC_{50}$ of 0.17, 0.19 and 27.5 ppm, respectively. The inhibition of two flavonoids were non-competitive with substrate. Twenty authentic flavonoids were tested in order to investigate structure-activity relationship. No significant relationship was found in them, however, catechol moiety of B-ring and 7-OH group in flavonoid skeleton were seemed to be responsible for the stronger activity.

• Archives of Pharmacal Research
• /
• 제24권4호
• /
• pp.292-296
• /
• 2001

Three prolyl endopeptidase (PEP) inhibitors were isolated from the methanolic extract of green tea leaves. They were identified as (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (+)-gallucatechin gallate with the $IC_{50}$ values of 1.42${\times}$$10^{-4}$mM, $1.02{\times}10^{-2}$mM, and $1.09{\times}10^{-4}$mM, respectively. They were non-competitive with a substrate in Dixon plots and did not show any significant effects against other serine proteases such as elastase, trypsin, and chymotrypsin, suggesting that they were relatively specific inhibitors against PER The isolated compounds are expected to be useful for preventing and curing of Alzheimer's disease.