• Title/Summary/Keyword: amino acid inhibition

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Study on the Antioxidative Effects and Amino Acid Contents of the Roots of Cynanchum Wilfori (백하수오(白何首烏)의 항산화활성(抗酸化活性)과 amino acid의 분포(分布)에 관한 실험적(實驗的) 연구(硏究))

  • Han Ki-Sun;Shin Gil-Jo;Lee Won-Chul;Lee Jong-Hyung
    • The Journal of Internal Korean Medicine
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    • v.19 no.2
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    • pp.411-430
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    • 1998
  • The aim of the presents study is to investigate and compare the antioxidative effects and qualities of the cultivating root of Cynanchum Wilfori, which is increasingly used in recent days, with those of the wilding root, which has mainly been used in the past in oriental medicine for a tonic and also for prevention and treatment of various geriatric diseases including aging progress. For comparison of their antioxidative effects, the activities of the total extracts on lipid peroxidation and the activity of aldehyde oxidase(EC 1.2.3.1) as well as xanthine oxidase(EC 1.2.3.2) were investigated in vitro. In addition, their inhibitory effects on the activity of 5-lipoxygenase, which is known to induce inflammation and concerned with free radicals, were also determined in vitro. Furthermore, the amino acid contents of both roots were analyzed in order to compare their qualities. The results are as follows: 1. The wilding root inhibited significantly the activity of 5-lipoxygenase, showing five times more portent than the cultivating root. 2. Both of the wilding root and the cultivating root inhibited aldehyde oxidase activity in a dose-dependant manner. The wilding root was more effective than the other. 3. Both of the wilding root and the cultivating root dose-dependently suppressed lipid peroxidation in rat brain, kidney, and liver. 4. The anti-peroxidative effects of both roots appeared to be most strong in brain and least in liver. In particular, the cultivating root exhibited a significant inhibition on brain lipid peroxidation. 5. The cultivating root contained 15 amino acids including five essential amino acids in contrast with the less contents in the wilding root.

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Evaluation of Antioxidant Activities of Peptides Isolated from Korean Fermented Soybean Paste, Chungkukjang

  • Kim, Sun-Lim;Chi, Hee-Youn;Kim, Jung-Tae;Hur, On-Sook;Kim, Deog-Su;Suh, Sae-Jung;Kim, Hyun-Bok;Cheong, Ill-Min
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.4
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    • pp.349-360
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    • 2011
  • The objectives of present study were to characterize the peptides which were isolated from Korean fermented soybean paste, chungkukjang, and to determine their antioxidant activities. Four fractions were collected from the methanol extract of chungkukjang by using a recycling preparative HPLC. Among fractions, Fr-2 was identified to be highly potent free radical scavenging activity in the assay of 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and nitroblue tetrazolium(NBT)-reduction inhibition. Base on antioxidant effects, fraction Fr-2 was employed for the refraction with a prep-column and separated into five fractions of which two fractions were identified to have higher antioxidant activity. To confirm the amino acid constituents of antioxidant fractions Fr-2-2 and Fr-2-3 were analyzed, and eight kinds of amino acids such as aspartic acid, threonine, serine, glutamic acid, glycine, lysine, histidine, and arginine were identified as the constituent amino acids. Antioxidant activities of the separated peptides were further assessed cell viability with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl terazolium bromide (MTT), and fluorescence-activated cell sorting (FACS) analysis of H4IIE cells treated with hydrogen peroxide (H2O2). Chungkukjang peptides have shown their ability to protect H4IIE rat hepatoma cells against H2O2- induced oxidative stress by concentration and time-dependent manner. Therefore, These results indicated that fermented soybean paste chungkukjang will be promoted the antioxidant and radical scavenging activities, and beneficial for health. The antioxidant peptide fractions Fr-2-2 and Fr-2-3 were denominated as P-NICS-1 and P-NICS-2, respectively. However, further studies were required to clarify their amino acid sequences and molecular properties, and physiological significances.

Studies on Active Center of $(Na^{+}+K^{+})-ATPase$ in Rabbit Red Cell Membranes (토끼 적혈구막의 $(Na^{+}+K^{+})-ATPase$의 active center에 관한 연구)

  • Lim, Bo-Sang
    • The Korean Journal of Physiology
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    • v.9 no.1
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    • pp.1-11
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    • 1975
  • The present experiments were carried out to investigate the active center of sodium and potassium ion activated adenosine triphosphatase. An ATPase, activated by sodium ion Plus potassium ion in the presence of magnesium ion, and inhibited by ouabain, has been obtained from rabbit red cell ghosts. The ATPase activity was measured by inorganie phosphate released from ATP. From this values of the measured inorganic phosphate, the activity of ATPase was calculated. The following results were observed. 1. The activity of $(Na^++K^+)-ATPase$ is inhibited by ouabain. This effect may not be due to an effect on sulfhydryl groups, amino groups, carboxyl groups, imidazole groups and hydroxyl groups. 2. The $(Na^++K^+)$-activated enzyme system is inhibited by p-chloromercuribenzoate and by d nitroflurobenzene, and this effect may be due to an effect on sulfhydryl groups. These results indicate that the sulfhydryl groups is attached to sodium-potassium dependent adenosine triphosphate, an aspect of the pump. 3. The $(Na^++K^+)-activated$ enzyme system is inhibited by maleic anhydride and this inhibition is reversed by lysine. This Seems to indicate that the active center of this enzyme is the amino groups. 4. The $(Na^++K^+)$-activated enzyme system is inhibited by iodoacetamide and this inhibition is reversed by the simultaneous present of cysteine and aspartic acid in the suspension medium. This result indicates that this enzyme contains sulfhydryl groups and carboxyl groups. 5. The $(Na^++K^+)-ATPase$ activity is accelerated by adrenaline and this effect is abolished by aspartic acid. This effect of aspartic acid indicate that carboxyl group might be involved in the hydrolysis of ATP by the enzyme system. On the hydrolysis of ATP by the enzyme system. On the basis of these experiments it f·as suggested that the active center of $(Na^++K^+)-activated$ ATPase contains sulfhydryl groups, amino groups and carboxyl groups.

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Inhibition of Carboxypeptidase A with$\beta$-Lactone-bearing phenylalanine. Design, Synthesis, and Stereochemistry-dependent Inhibition Mode

  • Lee, Mi Jun
    • Bulletin of the Korean Chemical Society
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    • v.22 no.11
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    • pp.1236-1242
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    • 2001
  • (3S,1'S)-3-(1'-Carboxy-2'-phenyl)ethylamino-2-oxetanone (1a) and (3R,1'S)-3-(1'-carboxy-2'-phenyl)ethylamino-2-oxetanone (1b) were designed, synthesized, and evaluated as inhibitors for carboxypeptidase A, a prototypical zinc protease that removes the C-terminal amino acid having an aromatic side chain from oligopeptide substrate. It was concluded from the analysis of inhibition kinetics that while 1a inactivates CPA irreversibly, its diastereoisomer, 1b is a weak competitive inhibitor for CPA. A possible explanation for the observed difference in inhibition mode that is dependent on the inhibitor stereochemistry is offered.

Effects of Protoberberine Compounds on Serotonin Content in P815 Cells (Protoberberine 화합물이 P815 세포중의 serotonin 함량에 미치는 영향)

  • Lee, Myung-Koo;Kim, Eung-Il;Hur, Jae-Doo;Lee, Kyong-Soon;Ro, Jai-Seup
    • Korean Journal of Pharmacognosy
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    • v.32 no.1 s.124
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    • pp.49-54
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    • 2001
  • The effects of protoberberine compounds on serotonin biosynthesis in P815 cells were investigated. Protoberberine compounds such as berberine, palmatine and coralyne decreased serotonin content dose-dependently, but coptisine did not. The $IC_{50}$ values of berberine, palmatine and coralyne were $3.0\;{\mu}M,\;16.5\;{\mu}M\;and\;14.5\;{\mu}M$, respectively. Protoberberine compounds at concentrations up to $20\;{\mu}M$ were not cytotoxic towards P815 cells. The activity of tryptophan hydroxylase, a ratelimiting enzyme in serotonin biosynthesis, was inhibited by the exposure of berberine, palmatine and coralyne in P815 cells (14.9-19.3% inhibition at $2-15\;{\mu}M$), but that of aromatic L-amino acid decarboxylase was not. These results suggest that the inhibition of tryptophan hydroxylase activity by berberine, palmatine and coralyne might partially contribute to the decrease in serotonin content in P815 cells.

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Natural Inhibitors for $CO_2$ Hydrate Formation (천연 물질을 이용한 이산화탄소 하이드레이트 형성 억제)

  • Sa, Jeong-Hoon;Lee, Bo Ram;Park, Da-Hye;Han, Kunwoo;Chun, Hee Dong;Lee, Kun-Hong
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.122.1-122.1
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    • 2011
  • The motivation for this work was the potential of hydrophobic amino acids such as glycine, L-alanine, and L-valine to be applied as thermodynamic hydrate inhibitors (THIs). To confirm their capabilities in inhibiting the formation of gas hydrates, three-phase (liquid-hydrate-vapor) equilibrium conditions for carbon dioxide hydrate formation in the presence of 0.1 to 3.0 mol% amino acid solutions were determined in the range of 273.05 to 281.45 K and 14.1 to 35.2 bar. From quantitative analyses, the inhibiting effects of the amino acids (on a mole concentration basis) decreased in the following order: L-valine > L-alanine > glycine. The application of amino acids as THIs has several potential advantages over conventional methods. First, the environmentally friendly nature of amino acids as compared to conventional inhibitors means that damage to ecological systems and the environment could be minimized. Second, the loss of amino acids in recovery process would be considerably reduced because amino acids are non-volatile. Third, amino acids have great potential as a model system in which to investigate the inhibition mechanism on the molecular level, since the structure and chemical properties of amino acids are well understood.

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Studies on the Drug Resources of Caryophyllaceae Plants -Free amino acids and antimicrobial activity- (석죽과식물(石竹科植物)의 의약자원(醫藥資源)에 관(關)한 연구(硏究) -유리(遊離)아미노산(酸)과 항균작용(抗菌作用)-)

  • Chung, Dong-Kyu;Kim, Tae-Hee;Kim, Mong-Ja
    • Korean Journal of Pharmacognosy
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    • v.9 no.2
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    • pp.77-82
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    • 1978
  • Free anino acid contents in alcohol extract of eight plants of Caryophyllaceae and their microbial activities were investigated. 1) Amino acid contents in both of the Pseudostellaria palibiniana and Stellaria media was the highest among them and the contents was less in the order of Cerastium caspitosum and Stellaria aquatica. 2) Of all free amino acids contained in eight plants, valine was the richest, and then glutamic acid, leucine in that order. On the other hand, no methionine was observed and cystine, lysine and histidine were found in small amounts. 3) Of eight plants exhibited good antibacterial action against Sarcina lutea, B. subtilis and Sal. typhi. 4) S.aquatica and Pseudostellaria palibiniana showed antibiotic actions against all bacteria except for fungus, Candida albicans. 5) C. caspitosum and C. brachypetalum showed inhibition zone against B. subtilis and Sal. typhi only. 6) Antibacterial activity against gram(+) bacteria was more potent than gram(-).

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Effects of leucine-enriched essential amino acid supplementation on muscular fatigue and inflammatory cytokines in wheelchair basketball players

  • An, Young Hwan;Kim, Jisu;Kim, Hee-Jae;Lim, Kiwon
    • Korean Journal of Exercise Nutrition
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    • v.24 no.2
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    • pp.38-46
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    • 2020
  • [Purpose] This study aimed to investigate the effects of leucine-enriched essential amino acid (LEAA) supplementation on muscle fatigue and the level of inflammatory cytokines in wheelchair basketball players after a basketball game and interval training. [Methods] Of the ten recruited wheelchair basketball players (aged 34.5±8.9 years; lean body mass of 34.3±10.0 kg) who had spinal cord injury (SCI) and had undergone amputation, nine participated in the final test. These nine athletes received LEAA supplements (3 times 4.0 g/day) or placebo treatment in a double-blind, randomized, crossover study. We measured variables related to muscular fatigue and inflammatory response before the intense exercise and 4 days after recovery. [Results] The significant effect of LEAA supplementation was inhibition of circulating IL-6 levels in the LEAA-treated group compared with the placebo group (P < .05). However, no changes were observed in the TNF-α and creatinine kinase levels. Moreover, analysis of variance analysis showed no significant difference in the relative values of muscle soreness. However, the effect size analysis with Cohen's d reported a significant improvement in the relative values of whole body and back muscle soreness. [Conclusion] Our results revealed that LEAA supplementation before and after intense exercise could help reduce muscle soreness and IL-6 levels in wheelchair basketball players.

Separation and Purification of Angiotensin Converting Enzyme Inhibitory Peptides Derived from Goat's Milk Casein Hydrolysates

  • Lee, K.J.;Kim, S.B.;Ryu, J.S.;Shin, H.S.;Lim, J.W.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.5
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    • pp.741-746
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    • 2005
  • To investigate the basic information and the possibility of ACE-inhibitory peptides for antihypertension materials, goat's caisin (CN) was hydrolyzed by various proteolytic enzymes and ACE-inhibitory peptides were separated and purified. ACE-inhibition ratios of enzymatic hydrolysates of goat's CN and various characteristics of ACE-inhibitory peptides were determined. ACE-inhibition ratios of goat's CN hydrolysates were shown the highest with 87.84% by pepsin for 48 h. By Sephadex G-25 gel chromatograms, Fraction 3 from goat's CN hydrolysates by pepsin for 48 h was confirmed the highest ACE-inhibition activity. Fraction 3 g and Fraction 3 gh from peptic hydrolysates by RP-HPLC to first and second purification were the highest in ACE-inhibition activity, respectively. The most abundant amino acid was leucine (18.83%) in Fraction 3 gh of ACE-inhibitory peptides after second purification. Amino acid sequence analysis of Fraction 3 gh of ACE-inhibitory peptides was shown that the Ala-Tyr-Phe-Tyr, Pro-Tyr-Tyr and Tyr-Leu. IC$_{50}$ calibrated in peptic hydrolysates at 48 h, Fraction 3, Fraction 3 g and Fraction 3 gh from goat's CN hydrolysates by pepsin for 48 h were 29.89, 3.07, 1.85 and 0.87 g/ml, respectively. Based on the results of this experiment, goat's CN hydrolysates by pepsin were shown to have ACE-inhibitory activity.

Effect of Peroxidized Lipid on the Protein Isolate and Protease Activity of Rice Bran (미강의 산화 지질이 단백질과 효소의 활성에 미치는 영향에 관한 연구)

  • Song, Yeong-Ok;Choi, Hong-Sik
    • Korean Journal of Food Science and Technology
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    • v.22 no.5
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    • pp.590-595
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    • 1990
  • The destructive effect of peroxidized lipid on the amino acid in protein isolate and the proteolytic activity of protease were studied in the model system of rice bran. The content of amino acids in the protein isolate decreased significantly when they reacted with peroxidized lipid (pov. 1200 meq/kg). Most of amino acids were lost by more than 90% in salt soluble protein isolates when analyzed by the method of enzyme hydrolysis. Formaldehyde reduced the activity most severely among peroxidized products. Formic acid, peroxidized lipid and hydroperoxide were also found to reduce the protease activity. The damaging effect of the secondary products on the protease activity was more serious than that of the primary products of lipid peroxidation. The destruction of amino acids in the total protein and Inhibition of protease activity by the peroxidized lipid were apparent.

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