• Fisheries and Aquatic Sciences
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• 제8권2호
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• pp.109-112
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• 2005

A peptide that inhibits angiotensin-converting enzyme (ACE) was isolated from a hydrolysate of Manila clam (Ruditapes philippinarum) proteins prepared with thermolysin. Amino acid sequence of the peptide was determined to be Leu-Leu-Pro. Chemically synthesized Leu-Leu-Pro had an $IC_{50}\;value\;of\;158\;\mu{M}$. Peptides related to the Manila clam-derived peptide were synthesized to study the structure-activity relationships. The tetrapeptide, Leu-Leu-Pro-Pro, had a very weak effect on the enzyme. However, Leu-Leu-Pro-Asn showed no inhibitory activity.

• 대한전자공학회논문지SD
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• 제48권11호
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• pp.41-47
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• 2011

산업용 표준 센서 신호처리를 위해 다양한 입력신호를 5V 전압 출력으로 변환하는 새로운 디지털 계측 증폭기(DIA)를 설계하였다. 이 계측 증폭기는 상용의 계측증폭기, 7개의 아날로그 스위치, 2개의 1.0V와 -10.0V의 기준전압, 그리고 4개의 저항기로 구성된다. 신호 변환원리는 입력신호에 따라 저항기와 기준전압을 디지털적으로 선택하여 5V의 출력전압을 얻도록 회로 구성을 바꾸는 것이다. 시뮬레이션 결과 DIA는 0V~5V, 1V~5V, -10V~+10V, 그리고 4mA~20mA의 입력신호에 대하여 우수한 0~5V 출력전압 특성을 얻을 수 있다는 것을 확인하였다. 4가지 입력 신호에 대하여 비선형오차는 0.1%이하이다.

• Biomolecules & Therapeutics
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• 제1권2호
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• pp.220-225
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• 1993

Effect of BR-900317 on the angiotensin I-induced pressor response in pithed rats and the effects of its single oral administration on plasma angiotensin converting enzyme (ACE) activities in normotensive rats and on the cardiovascular system in hypertensive model rats (SHR, RHR), were compared with those of captopril. BR-900317 attenuated the angiotensin I-induced pressor effects in pithed rats. In a single oral dose administration study, BR-900317 inhibited the plasma ACE activities in a dose-dependent fashion. Duration of the action of BR-900317 was similar to that of captopril. BR-900317 produced antihypertensive effect in spontaneously hypertensive rats and dose-dependent antihypertensive effect in 2-kidney Goldblatt hypertensive rats without affecting heart rate. These results suggest that the main mechanism of the antihypertensive effect of BR-900317 is the suppression of angiotensin II production due to the inhibition of the ACE.

• Journal of Microbiology and Biotechnology
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• 제14권6호
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• pp.1318-1323
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• 2004

This study describes the purification and characterization of a novel antihypertensive angiotensin 1­converting enzyme (ACE) inhibitory peptide from Saccharomyces cerevisiae. Maximal production of the ACE inhibitor from Saccharomyces cerevisiae was obtained from 24 h of cultivation at $30^{\circ}C$ and its ACE inhibitory activity was increased by about 1.5 times after treatment of the cell-free extract with pepsin. After the purification of ACE inhibitory peptides with ultrafiltration, Sephadex G-25 column chromatography, and reverse-phase HPLC, an active fraction with an $IC_{50}$ of 0.07 mg and $3.5\%$ yield was obtained. The purified peptide was a novel decapeptide, showing very low similarity to other ACE inhibitory peptide sequences, and its amino acid sequence was Tyr-Asp-Gly-Gly-Val-Phe-Arg-Val-Tyr-Thr. The purified inhibitor competitively inhibited ACE and also showed a clear antihypertensive effect in spontaneously hypertensive rats (SHR) at a dosage of 1 mg/kg body weight.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.757-763
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• 2006

Angiotensin I-converting enzyme (ACE) inhibitors have generally been very useful to remedy or prevent hypertension. This study describes the extraction and characterization of an ACE inhibitor from the fruiting body of Pholiota adiposa ASI 24012, which can be used as an antihypertensive drug. The maximal ACE inhibitory activity $(IC_{50};0.25mg)$ was obtained when the fruiting body of Pholiota adiposa ASI 24012 was extracted with distilled water at $30^{\circ}C$ for 12 h. After the purification of ACE inhibitor with ultrafiltration, Sephadex G-25 column chromatography, and reverse-phase HPLC, an active fraction with an $IC_{50}$ of 0.044 mg was obtained. The purified ACE inhibitory peptide was a novel pentapeptide, showing very little similarity to other ACE inhibitory peptide sequences. The molecular mass of the purified ACE inhibitor was estimated to be 414 daltons with a sequence of Gly-Glu-Gly-Gly-Pro, and showed a clear antihypertensive effect on spontaneously hypertensive rats (SHR) at a dosage of 1 mg/kg.

• Nutrition Research and Practice
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• 제5권2호
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• pp.93-100
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• 2011

Inhibition of angiotensin I-converting enzyme (ACE) activity is the most common mechanism underlying the lowering of blood pressure. In the present study, five organic extracts of a marine brown seaweed Ecklonia cava were prepared by using ethanol, ethyl acetate, chloroform, hexane, and diethyl ether as solvents, which were then tested for their potential ACE inhibitory activities. Ethanol extract showed the strongest ACE inhibitory activity with an $IC_{50}$ value of 0.96 mg/ml. Five kinds of phlorotannins, phloroglucinol, triphlorethol-A, eckol, dieckol, and eckstolonol, were isolated from ethanol extract of E. cava, which exhibited potential ACE inhibition. Dieckol was the most potent ACE inhibitor and was found to be a non-competitive inhibitor against ACE according to Lineweaver-Burk plots. Dieckol had an inducible effect on the production of NO in EAhy926 cells without having cytotoxic effect. The results of this study indicate that E. cava could be a potential source of phlorotalnnins with ACE inhibitory activity for utilization in production of functional foods.

• 사상체질의학회지
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• 제14권1호
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• pp.132-139
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• 2002

The correlation between angiotensin converting enzyme (ACE) polymorphisms and cerebral infarction (CI) has been controversial. Such controversy may be due to different classifications of cerebrovascular diseases and ethnic differences. I studied the correlation between ACE genotypes and CI patients by case-control study in the Korean population. I also classified CI patients and control group into four types according to Sasang constitutional medicine. Furthermore I investigated the correlation among ACE genotypes, CI and Sasang constitutions. The frequencies of D allele were 0.32 in subjects with CI and 0.40 in the control group without CI (X2=0.128, p=0.720). In patients with CI, the frequency of Taeumins, one of four Sasang constitutional types, was significantly higher than that in controls (X2=15.425, p<0.00l). I did not find any correlation between ACE polymorphism and CI in Koreans. However, there were significant differences in allele frequencies between Koreans and Europeans, while similarities were shown to those of Japanese and Chinese populations.

• Journal of Acupuncture Research
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• 제20권2호
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• pp.161-172
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• 2003

Objective : This study was designed to investigate the relation between the angiotensin converting enzyme(ACE) gene polymorphism and stroke in the Korean population. Methods : This study was carried out on 58 stroke patients who were hospitalized in the department of acupuncture & moxibustion, college of Oriental Medicine, Kyung-Hee University and 61 healthy control subjects. Blood samples from all subjects were obtaind for DNA extration. The extracted DNA was amplified by polymerase chain reaction(PCR). PCR products were visualized by 2% agarose gel electrophoresis. Results : The sub-genotypes of ACE gene were II homozygotes, ID heterozygotes, DD homozygotes. While the distribution of ACE polymorphism in control subjects was 31%, 51%, 18%, the distribution of it in stoke patients was 33%, 52%, 16%(II, ID, DD). Thus, there was no significant different between the control and stroke groups. Conclusions : we conclude that there is no significant association between ACE gene polymorphism and storke in Korean papulation. However, the findings of this study need to be confirmed in large patients and further studies. Additional epidemiologicallly based studies of the effects and relationship between ACE or other genes and lifesyles with regard to stroke required.

• Ocean Science Journal
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• 제41권2호
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• pp.97-104
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• 2006

A useful radiance-converting method was developed to convert the Landsat-7 ETM+thermal-infrared (TIR) band's radiance ($L_{{\lambda},L7/ETM+}$) to that of Landsat-5 TM TIR ($L_{{\lambda},L5/TM+})$ as: $L_{{\lambda},L5/TM}=0.9699{\times}L_{{\lambda},L7/ETM+}+0.1074\;(R^2=1)$. In addition, based on the radiance-converting equation and the linear relation between digital number (DN) and at-satellite radiance, a DN-converting equation can be established to convert DN value of the TIR band between Landsat-5 and Landsat-7. Via this method, it is easy to integrate Landsat-5 and Landsat-7 TIR data to retrieve the sea surface temperature (SST) in coastal waters on the basis of local empirical algorithms in which the radiance or DN of Lansat-5 and 7 TIR band is usually the only input independent variable. The method was employed in a local empirical algorithm in Daya Bay, China, to detect the thermal pollution of cooling water discharge from the Daya Bay nuclear power station (DNPS). This work demonstrates that radiance conversion is an effective approach to integration of Landsat-5 and Landsat-7 data in the process of a SST retrieval which is based on local empirical algorithms.

• Biomolecules & Therapeutics
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• 제2권1호
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• pp.34-38
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• 1994

In order to investigate the structure-activity relationships of the stereoisomers of angiotensin converting enzyme inhibitors, captopril and its derivatives were selected as model compounds. In vitro enzymatic activities of them depend on the symmetry at the asymmetric carbons. Especially, the alanyl carbon should have the S configuration to be biologically active. But the demethylated captopril having the achiral carbon also shows the activity although it is less active than captopril. Seven stereoisomers of captopril and its derivatives were chosen and their acidic and ionic forms were used for molecular dynamics simulations. Four computer simulations were practiced for each model compound in order to obtain the good condition for simulation to explain the experimental structure-activity relationships. From the computer simulation results, relativistic movements of three well-known pharmacophoric sites, carboxylate carbon, carbonyl oxygen, and sulfur atoms, were analyzed. Good results were obtained from the aqueous solution molecular dynamics simulation with ionic forms of model compounds. Active model compounds have the pharmacophoric areas of 6.08 to 6.38 $\AA$$^2$and the similarity in the geometrical data. But inactive ones have the largely deviated values of 4.51 to 4.87 $\AA$$^2$from those of active ones.