• Asian-Australasian Journal of Animal Sciences
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• v.16 no.9
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• pp.1369-1373
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• 2003

ACE (Angiotensin-I converting enzyme) inhibitory peptides derived from foods are thought to suppress high blood pressure by inhibiting ACE. We tried to make efficient production of the ACE inhibitory hydrolysate from egg albumen. A hydrolysate digested by neutrase presented the highest ACE inhibitory activity ($IC_50\;value=256.35{\mu}g/ml$) and the proper proteolysis was occurred by 1.0% enzyme addition and 4 h incubation at $47^{\circ}C$. Antihypertensive effect of neutrase hydrolysate was investigated in spontaneously hypertensive rats (SHR, n=5). Systolic blood pressure (SBP) was decrease by 6.88% (-14.14 mmHg, p<0.05) at 3 h after oral administration of 300 mg/kg body weight, and by 13.33% (-27.72 mmHg, p<0.05) by emulsified hydrolysate. These results showed that it is very effective to utilize egg albumen as a protein source for the production of ACE inhibitory peptides. However, further studies are required to investigate the methods to increase recovery yield and the isolation of active peptide is necessary for determining its sequence responsible for ACE inhibitory activity.

• ALGAE
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• v.21 no.3
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• pp.343-348
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• 2006

This study was conducted to screen in vitro angiotensin - I converting enzyme (ACE) inhibitory activities of methanol (MeOH) and aqueous extracts at 20°C and 70°C, respectively, prepared from twenty-six red algae obtained from the coast of Jeju Island in Korea. Among aqueous extracts at 20°C (20AE) from red algae Lomentaria catenata showed the strongest ACE inhibitory activity and Lithophyllum okamurae recorded the second highest activity. From MeOH extract at 20°C (20ME) Ahnfeltiopsis flabelliformis possessed the strongest ACE inhibitory activity. Remarkable activities from MeOH extracts at 70°C (70ME) were observed in Grateloupia filicina, Sinkoraena lancifolia and Grateloupia lanceolata. However, no significant activity was found in aqueous extracts at 70°C (70AE). The IC50 values, which are concentrations required to inhibit 50% activity of ACE, for ACE inhibitory activities of 20AE from Lithophyllum okamurae and L. catenata were 13.78 and 12.21 μg mL–1, respectively. The IC50 values of 20ME from A. flabelliformis and Laurencia okamurae were 13.84 and 106.15 μg mL–1. Those of the 70ME from Bonnemaisonia hamifera, Grateloupia filicina, Sinkoraena lancifolia, G. lanceolata, Gracilaria vermiculophylla and L. okamurae ranged from 25.82 to 124.69 μg mL–1.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.430-436
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• 2019

Objective: This study identified angiotensin I-converting enzyme (ACE) inhibitory peptides in beef M. longissimus injected with thermolysin (80 ppm) and stored for 3 days at $5^{\circ}C$. Methods: Crude peptides (molecular weight <3 kDa) were obtained from the thermolysin hydrolysate and separated into seven fractions. Fraction V showing the highest ACE inhibitory activity was further fractionated, yielding subfractions V-15, V-m1, and V-m2, and selected for superior ACE inhibitory activity. Finally, twelve peptides were identified from the three peak fractions and the ACE inhibitory activity ($IC_{50}$) of each peptide was evaluated. Results: The Leu-Ser-Trp, Phe-Gly-Tyr, and Tyr-Arg-Gln peptides exhibited the strongest ACE inhibitory activity ($IC_{50}$ values of 0.89, 2.69, and 3.09 mM, respectively) and had higher concentrations (6.63, 10.60, and 29.91 pg/g; p<0.05) relative to the other peptides tested. Conclusion: These results suggest that the thermolysin injection process is beneficial to the generation of bioactive peptides with strong ACE inhibitory activity.

• Mycobiology
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• v.39 no.1
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• pp.67-69
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• 2011

A cell-free extract of Saccharomyces cerevisiae containing the angiotensin I-converting enzyme (ACE) inhibitory peptide was treated in a successive simulated gastric-intestinal bioreactor (step 1: amylase digestion, step 2: gastric fluid digestion, step 3: intestinal fluid digestion) to illustrate the absorption pattern of antihypertensive ACE inhibitory peptide, and the ACE inhibitory activities of each step were determined. Total ACE inhibitory activities of step 1, step 2, and step 3 were 55.96%, 80.09%, and 76.77%, respectively. The peptide sequence of each steps was analyzed by MS/MS spectrophotometry. Eleven kinds of representative peptide sequences were conserved in each step, and representative new peptides including RLPTESVPEPK were identified in step 3.

• Nutrition Research and Practice
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• v.5 no.2
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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.

• The Journal of Natural Sciences
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• v.16 no.1
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• pp.1-13
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• 2005

The angiotensin I-converting enzyme (ACE) inhibitor has anti-hypertensive effects and has long been used as prevention or remedy of hypertension. This study were carried out to produce and purify a new ACE inhibitor from recombinant E. coli and further elucidate its structure-function relationship. Recombinant pGEX-4T-3 containing ACE inhibitory peptide gene of Saccharomyces cerevisiae was transformed into E. coli BL21(DE3). Glutathione-S transferase (GST) fusion protein from E. Coli BL21(DE3) harboring the recombination pGEX-4T-3 was obtained and the ACE inhibitory peptide was purified with Sephadex G-25 column chromatography. The purified ACE inhibitory peptide was a novel decapeptide with sequence Tyr-Asp-Gly-Gly-Val-Phe -Arg-Val-Tyr-Thr which shows very low similarity to the other ACE inhibitory peptide sequence. The purified ACE inhibitor competitively inhibited ACE.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.848-854
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• 1999

Inhibitory compounds of angiotensin converting enzyme (ACE) were separated from Doenjang (traditional Korean fermented soybean paste). Water extracts from Doenjang which showed ACE inhibitory activity were separated with gel permeation chromatography (GPC), in which two fractions with high ACE inhibitory activities were obtained. The first fraction from GPC was further isolated by semi-preparative reverse phase preparative-HPLC (high performance liquid chromatography) and 2-dimensional electrophoresis/thin layer chromatography (TLC). The purified spot had molecular weight of 759 daltons and ninhydrin-positive non-peptide. The second fraction from GPC was also further isolated by semi-preparative reverse phase HPLC and $NH_2-column$ HPLC. One fraction with high ACE inhibitory activity was purified and characterized. Molecular weight of this fraction by LC-MS was 272.34 daltons. The active fraction was identified as Arg-Pro with ACE $IC_{50}$ of $92\;{\mu}M$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.2
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• pp.226-233
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• 1993

Enzymatic hydrolysates of food proteins (defatted soybean cake, egg albumin and casein) were tested for inhibitory activity against angiotensin-I converting enzyme (ACE). Food proteins were hydrolysed with complex enzyme, bromelain, alcalase, $\alpha$-chymotrypsin, trypsin, papain and pepsin by heating method. The hydrolysates obtained from the treatment of complex enzyme and bromelain showed the higher ACE inhibitory activity. ACE inhibitory activity of hydrolysates exhibited a tendency to be increased until 8hrs and increased with increment of concentration. The activity was also stable by heat treatment at 10$0^{\circ}C$ for 20min. Molecular weight of active fraction was about 1, 400 and defatted soybean cake hydrolysate below 1, 400 in case of defatted soybean cake hydrolysate treated with alcalase. Amino acid of the active fractions was abundant in Asp, Glu, Lys, lle, Leu, Ala and Val.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.164-172
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• 2001

The angiotensin-I converting enzyme (ACE) inhibitors from laver hydrolysate was isolated. Among the 13 kinds of proteases, Maxazyme NNP was most effective for preparing the high ACE inhibitory compound. In extraction conditions of ACE inhibitory peptide from laver hydrolysate, ACE inhibitory activity of hydrolysate treated with diethylether for decolorization and that of $70\%$ ethanol soluble fraction among the different ethanol concentrations were higher than other preparations. Low molecular fraction less than 3,000 dalton of layer hydrolysate separated by ultrafiltration had the highest ACE inhibitory activity, for further separation of ACE inhibitory peptide from laver hydrolysate, gel filtration chromatography (Sephadex G-25), reverse-phase HPLC (ODS & Vydac C-18) and gel permeation chromatography (Superdex Peptide HR) were performed. The molecular mass of the ACE inhibitory peptide fractions of gel permeation chromatography determined by electrospray-mass spectrometer were 413.48 (S1O2V2V1P),346.86 (S1O2V2V2P) and 320.32 (S2O6V3V1P) dalton and their amino acid sequence were Val-Gln-Gly-Asn, Thr-Glu-Thr and Phe-Arg, respectively.

• Preventive Nutrition and Food Science
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• v.10 no.3
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• pp.239-243
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• 2005

Angiotensin I-converting enzyme (ACE) inhibitory activities of elk antler hydrolysates prepared with three kinds of proteases, pepsin, trypsin and $\alpha-chymotrypsin$, were investigated. The ACE inhibitory activity of the pepsinolytic hydrolysate was the highest with an $IC_{50}$ value of $9.3\mu g/mL.$ In addition, three kinds of pepsinolytic hydrolysates with relatively high molecular weights (over 10,000 Da), medium molecular weights (5,000 to 10,000 Da), and low molecular weights (below 5,000 Da) were fractionated using an ultrafiltration membrane system. The below 5,000 Da hydrolysate exhibited the highest ACE inhibitory activity. These results indicate that the pepsinolytic hydrolysates of elk velvet antler could be a good source of peptides with ACE inhibitory activity.