• Korean journal of food and cookery science
• /
• v.10 no.1
• /
• pp.35-38
• /
• 1994

The growth extent of Leu. mesenteroides and Lac. plantarum in the medium which contain sterilized extract of each of garlic, red pepper powder, and onion was examined. Garlic and onion decreased the growth of Leu. mesenteroides and Lac. Plantarum, and garlic represented more negative effect on the growth of Lac. plantarum than that of onion. Red pepper powder had negative effect on the growth of Lac. plantarum, and positive effect on the growth of Leu. mesenteroides in accordance with incubation processing.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1997.05a
• /
• pp.108-113
• /
• 1997

하나로(HANARO)를 이용하여 핵분열 방법으로 진단용 방사선원인 $^{99m}$ Tc의 모핵종인 Mo-99를 생산할 경우, HEU 및 LEU UO2 표적이 사용될 수 있다. 표적연료로서 HEU(93w/o $^{235}$ U)가 LEU(19.75w/o $^{235}$ U)에 비해 생성수율(Ci/gU)이 높게 나타났으며 제품의 질(quality)을 좌우하는 비방사능(Ci$^{99}$Mo/gMo)은 같게 나타났다. HEU가 같은 Mo-99의 방사능량을 얻기 위해서는 우라늄 장전량이 적어지므로 폐기물측면과 용해측면에서 이득이나 농축도를 고려하면, 큰 이득이 발생하지 않으므로 하나로에 LEU를 사용하는 것도 타당하다 할 수 있다.

• Korean journal of food and cookery science
• /
• v.11 no.5
• /
• pp.511-520
• /
• 1995

The growth extent of Leuconostoc mesenteroides and Lactobacillus plantarum in the medium which contain sterilized extract of each kimchi minor ingredient (green onion, garlic, ginger, raw red pepper, and red pepper powder) was examined. All minor ingredients decreased the growth of Lac. plantarum, and this effect of garlic is the most distinctive, ginger had the positive effect on the growth of Leu. mesenteroides, and garlic had the negative effect on the growth of Leu. mesenteroides. When the growth extent of two bacteria in the medium which contain sterilized successive extracts of each of garlic, ginger and red pepper powder was examined, the butanol fraction of garlic was reprsented the negative effect on the growth of Leu mesenteroides and Lac. plantarum, and the water fraction of ginger and red pepper powder were represented the positive effect on the growth of Leu. mesenteroides.

• Analytical Science and Technology
• /
• v.35 no.3
• /
• pp.129-135
• /
• 2022

We tested the pre-treatment of alumina, leucine, alumina mixed with leucine at ratios of 9:1 (Al-Leu (9:1)) and 5:1 (Al-Leu (5:1)), and alumina mixed with sodium lactate at a ratio of 5:1 (Al-Lac (5:1)) on aged fingerprints (1, 7, 14, and 30 days after natural fingerprinting) before cyanoacrylate (CA) fuming to improve the development efficacy. As a result of the experiment, fingerprints with pre-treatment of alumina, leucine, Al-Leu (9:1), Al-Leu (5:1), and Al-Lac (5:1) showed better development efficacy (area and minutiae) than fingerprints without pre-treatment. Therefore, this modified CA fuming method improved the development efficacy with five pretreatments.

• Journal of Nutrition and Health
• /
• v.42 no.8
• /
• pp.714-722
• /
• 2009

The principal objective of this study was to determine the effects of leucine on body weight reduction in high fat diet-induced overweight rats. To induce overweight, six-month-old male Sprague-Dawley rats (n = 80) were divided into 8 groups; one group of 10 rats was fed on a normal fat diet and the remaining 70 rats were fed on a high-fat diet (40% of energy as fat) for 14 weeks. Then, 10 rats fed on the normal fat diet and another 10 rats fed on the high fat diet were sacrificed to identify overweight induction. The remaining 60 rats were divided randomly into 6 groups according to body weight and fed on one of the diets with different dietary fat levels (9.6% or 40% of energy as fat) and leucine levels (0, 0.6 or 1.2 g/kg BW) for the following 5 weeks of experiments. The body weight loss in the Leu-administered groups (0.6 g, 1.2 g/kg BW) was significantly higher than those of Leu non-administered groups. The perirenal fat pad weights in the Leu-administered groups were significantly lower than those of the Leu non-administered groups. Of the hepatic enzymes, glucose-6-phosphate dehydrogenase (G6PDH) activities were reduced significantly in the Leu-administered groups than in the Leu non-administered groups. With the oral glucose tolerance test (OGTT), the incremental areas under the curve of the glucose response (IAUC) of the Leu-administered groups were significantly lower than those of the Leu non-administered groups. The fasting glucose concentration and HOMA-IR of the Leu-administered groups were significantly lower than those of the Leu non-administered groups. In conclusion, the results of this study suggest that one of the possible mechanisms of leucine in the observed body weight reduction might involve the inhibition of lipogenic enzyme activities such as glucose-6-phosphate dehydrogenase, rather than the activation of lipolysis enzymes. Additionally, leucine adminstration resulted in improved glucose metabolism.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.3
• /
• pp.279-284
• /
• 2001

This paper reports the purification of myomodulin A (MMA) and myomodulin E (MME) from the sea hare. The central nervous systems of 500 sea hare were extracted in an acidified solvent, after which four HPLC column systems were used to obtain pure peptides, The phasic contraction bioassay using a Mytilus edulis anterior byssus retractor muscle (ABRW) was applied to monitor all collected fractions. The pure peptides were submitted to Edman degradation based automated microsequencing. Mass spectrometry and chemical synthesis confirmed the sequence. The primary structures of MMA and MME were Pro-Met-Ser-Met-Leu-Arg-Leu-$NH_2$, (847.41 Da) and Cly-Leu-Gln-Met-Leu-Arg-Leu-$NH_2$, (830.50 Da), respectively. Synthetic peptides showed a modulating activity of phasic contraction in the ABRM of Mrtilus edulis.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.4
• /
• pp.649-655
• /
• 2001

The kinetics of the thermolysin-catalyzed synthesis of N-(benzyloxycarbonyl)-L-phenylalanyl-L-leucine ethyl ester (Z-Phe-LeuOEt) from N-(benzyloxycarbonyl)-L-phyenylalanine (Z-Phe) and L-leucine ethyl ester (LeuOEt) in an ethyl acetate saturated aqueous system in a batch operation were studied. The kinetics for the synthesis of Z-Phe-LeuOEt were expressed using a rate equation for the rapid equilibrium random bireactant mechanism. The four kinetic constants involved in the rate equation were determined numerically by the quasi-Newton method so as to fit the calculated results with the experimental data. Within the pH and temperature range examined, the $K_{cat}$ value for the synthesis of Z-Phe-LeuOEt reached a maximum at pH 7.0 and $45^{\circ}C$, whereas the affinity between Z-Phe and thermolysin reached a maximum at pH 6.0 adn $40^{\circ}C$. The inhibitory effect of Z-Phe on the condensation reaction decreased as the pH and temperature decreased. In contrast, they affinity between LeuOEt and thermolysin remained unchanged within the pH and temperature range examined. Therefore, it was concluded that the protonation state of the carboxyl groups. of Z-Phe was more imprtant than that of the amono groups of LeuOEt for the synthesis of Z-Phe-LeuOEt in the present solvent system. The equilibrium yield at pH 6.0 and $30^{\circ}C$ was 8% higher than that at pH 7.0 and $40^{\circ}C$, although the rate was much slower. This result suggested that the affinity between the enzyme and the substrate rather than the overall rate was a more important factor affecting the equilibrium yield, when the peptide synthesis was carried out in a product-precipitation system.

• Journal of the Korean Chemical Society
• /
• v.43 no.5
• /
• pp.540-546
• /
• 1999

Solution conformation of cyclo-($Gln^1-Trp^2-Phe^3-{\beta}Ala^4-Leu^5-Met^6$), new NK-2 antagonist in dimethyl sulfoxide solution, has been determined by the use of two-dimensional nuclear magnetic resonance spectroscopy combined with simulated annealing calculations. The peptide exhibited converged structures with the atomic root-mean-square difference for the backbone atoms ($N,\;C^{\alpha},\;C'$) of all residues being 0.02${\AA}$ in the 25 annealed structures. The analysis of the structures indicated that the cyclic peptide has three intramolecular hydrogen bonds between $Met^6NH$ and ${\beta}Ala^4CO$, ${\beta}Ala^4NH$ and $Met^6CO$, $Phe^3NH$ and $Met^6CO$, and contain a type-I ${\beta}$-turn with Gln and Trp and ${\gamma}$-turn with Leu. The addition of an extra methylene group to Gly, i.e. P-Ala residue, may relax some unfavorable restraints in the cyclic backbone structure, hence enabling an additional hydrogen bond, which results in stabilizing one conformation.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.4
• /
• pp.874-880
• /
• 2010

A series of 13- and 14-membered cyclic enkephalin analogs based on the moderately $\mu$ selective prototype compound Tyr-C[D-$A_2bu$-Gly-Phe-Leu] 8a were synthesized to investigate the structure-activity relationship. The modifications of sequence were mainly focused on two positions 3 and 5, critical for the selective recognition for $\mu$ and $\delta$ opioid receptors. The substitution of hydrophobic $Leu^5$ with hydrophilic $Asp^5$ derivatives led to Tyr-C[D-$A_2bu$-Gly-Phe-Asp(N-Me)] 7 and Tyr-C[D-Glu-Phe-gPhe-rAsp(O-Me)] 5, the peptides with a large affinity losses at both $\mu$ and $\delta$ receptors. The substitution of $Phe^3$ with $Gly^3$ led to Tyr-C[D-Glu-Gly-gPhe-rLeu] 3 and Tyr-C[D-Glu-Gly-gPhe-D-rLeu] 4, the peptides with large affinity losses at $\mu$ receptors, indicating the critical role of phenyl ring of $Phe^3$ for $\mu$ receptor affinities. One atom reduction of the ring size from 14-membered analogs Tyr-C[D-Glu-Phe-gPhe-(L and D)-rLeu] 6a, 6b to 13-membered analogs Tyr-C[D-Asp-Phe-gPhe-(L and D)-rLeu] 1, 2 reduced the affinity at both $\mu$ and $\delta$ receptors, but increased the potency in the nociceptive assay, indicating the ring constrain is attributed to high nociceptive potency of the analogs. For the influence of D- or L-chirality of $Leu^5$ on the receptor selectivity, regardless of chirality and ring size, all cyclic diastereomers displayed marked $\mu$ selectivity with low potencies at the $\delta$ receptor. The retro-inverso analogs display similar or more active at $\mu$ receptor, but less active at $\delta$ receptor than the parent analogs.

• Journal of Animal Science and Technology
• /
• v.50 no.5
• /
• pp.649-656
• /
• 2008

The current study was undertaken to investigate the mechanism of action of insulin-like growth factors (IGFs) on proliferation and differentiation of pig preadipocytes. The preadipocytes were isolated from the backfat of new-born female pigs and cultured in serum-deprived medium in the presence and absence of recombinant native IGFs or recombinant mutant IGFs that have reduced affinity for binding to both type-1 IGF receptors and insulin receptors. Fifty ng/ml of either IGF-I, [Leu60]IGF-I, IGF-Ⅱ or [Leu27]IGF-Ⅱ were included in the media in which preadipocytes were cultured for 4 days. IGF-I, [Leu60]IGF-I, IGF-Ⅱ and [Leu27]IGF-Ⅱ stimulated proliferation of pig preadipocytes by 39%, 8%, 25% and 2% respectively, as measured by increased numbers of cells. This indicates that both IGF-I and -II promote replication of pig preadipocytes by actions mediated either by type-1 IGF receptor or insulin receptor. IGF-I, [Leu60]IGF-I, IGF-Ⅱ and [Leu27]IGF-Ⅱ stimulated differentiation of pig preadipocytes by 50%, 17%, 37% and 30%, respectively, measured as glycerolphosphate dehydrogenase activity. Reducing the affinity of IGF-I for type-1 IGF receptors or insulin receptors significantly reduced the differentiation response. However, the differentiation response to [Leu27]IGF-II was not significantly different from the response to IGF-II. This shows that IGF-I and IGF-Ⅱ promote cell differentiation by different receptor-mediated mechanisms. IGF-II promotes differentiation of pig preadipocytes by actions that do not involve either type-1 IGF receptors or insulin receptors. These actions therefore appear to be mediated by binding of IGF-II to type-2 IGF receptors(also known as cation-independendent mannose-6-phosphate receptor[CIM6P/IGF2 receptor]). This is the first study to find evidence that IGF-II promotes differentiation of preadipocytes from any animal species by actions mediated by CIM6P/IGF2 receptors. In summary, this study shows that IGF-I and IGF-Ⅱ promote differentiation of pig preadipocytes by mechanisms that involve different cellular receptors.