• Korean journal of food and cookery science
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• v.18 no.1
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• pp.87-93
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• 2002

Effect of copper ions (Cu$\^$+/ and Cu$\^$2+/) on the fermentation of kimchi, especially on their effect on the prevention of over-acidification of kimchi, was investigated. The effect of Cu$\^$2+/ ion on the growth of individual lactic acid bacterium originally isolated from kimchi was also investigated. The addition of Cu$\^$+/($\geq$4.0mM) or Cu$\^$2+/($\geq$3.0mM) ions in kimchi effectively inhibited growth of lactic acid bacteria and maintained a titratable acidity of less than 1.0% for a periods of 14 days. Leuconostoc mesenteroides significantly decreased at the 10th day of fermentation in control kimchi, whereas the group with Cu$\^$+/ and Cu$\^$2+/ showed 10$\^$5/-10$\^$6/ CFU/ml at the 14th day of fermentation. This indicates that the addition of Cu$\^$+/ and Cu$\^$2+/ inhibited the production of excessive acids by inhibiting lactic acid bacteria, and allowed Leu. mesenteroides stay alive longer. Fe$\^$2+/ and SO$_4$$\^$2-/ ions did not have any effect on the fermentation of kimchi. Cu$\^$2+/ inhibited growth of all lactic acid bacteria tested, such as Leu. mesenteroides 6, Streptococcus faecalis 12, Lactobacillus plantarum 14, Lac. brevis 15, Leu. mesenteroides LA 10, and Lac. plantarum LA 97.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.495-505
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• 1995

The purpose of this study was to identify the psychrotrophic lactic acid bacteria isolated from kimchi, a Korean traditional fermented vegetable food. Thirty isolates of psychrotrophic lactic acid bacteria were isolated randomly from kimchi-A and kimchi-B which were fermented at $5{\sim}7^{\circ}C$ for 20 days and 50 days, respectively. Among 30 isolates of lactic acid bacteria isolated from kimchi-A, 14 isolates were identified as Leuconostoc mesenteroides subsp. mesenteroides, 12 as Leuconostoc mesenteroides subsp. dextranicum and 4 as Lactobacillus bavaricus. Among 30 isolates isolated from kimchi-B, 20 isolates were identified as Lactobacillus bavaricus, 3 as Leuconostoc mesenteroides subsp. mesenteroides, 3 as Leuconostoc lactis, 2 as Leuconostoc paramesenteroides and 2 as Lactobacillus homohiochii. Though these strains were identified as above, there were many strains whose sugar fermenting patterns and $NH_3$ producing ability from arginine were inconsistent with those described in Bergey's Manual of Systematic Bacteriology, and some strains identified as Leuconostoc mesenteroides subsp. mesenteroides and Leuconostoc mesenteroides subsp. dextranicum even disclosed such contradictions as the comparisons of sugar fermenting patterns between the strains of different subspecies were much more coincident than those between the same subspecies. As there were difficulties in classifying these psychrotrophic lactic acid bacteria according to the current taxonomic system, further studies were needed to solve these problems.

• Journal of the Korean Society of Food Science and Nutrition
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• v.17 no.3
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• pp.242-248
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• 1988

Plasteins were synthesized from a peptic sardine protein hydrolysate by pepsin, ${\alpha}-chymotrypsin$ pretense(from Aspergillus saitoi) and papain under the optimum conditions of previous paper. L -glutamic acid diethylester and L-leucine ethylester also were incorporated into plastein during the plastein reaction by papain. General composition, yield, molecular weight and amino acid composition were measured. The protein, ash and lipid rontent of plasteins were $81.1{\sim}88.2%$, $1.9{\sim}7.6%$ and $0.3{\sim}0.8%$, respectively. The yield of plasteins were pretense plastein 52.3%, papain plastein 44.2%, pepsin plnstein 43.6%, ${\alpha}-chymotrypsin$ plastein 43.2%. Leu -papain plastein 33. 2% and Glu - papain plastein 29.0%. The glutamic acid and leucine content in Glu -papain plastein and Leu -papain plastein were 39.0%, 37.5%, respectively. While the contents in the papain plastein were 14.3%, 7.1%, respectively. The amino acid composition of plasteins were similar to that of peptic sardine protein hydrolysate. The major molecular weight of the peptic hydrolysnte estimated by gelfilteration were 1,800 and 285, and those of plasteins were 26,000 and 9,100 for ${\alpha}-chymotrypsin$, 23,000, 10,000 and 4,300 for pepsin, 18,000 for pretense, 13,000 for papain, 29,000 for Leu -papain plastein and 19,000 for Glu -papain plastein.

• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.461-468
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• 1999

Acetolactate synthase (ALS) catalyzes the first common reaction in the biosynthesis of branched-chain amino acids, valine, leucine, and isoleucine. ALS is the common target of several classes of structurally diverse herbicides, the triazolopyrimidines, the imidazolinones, the sulfonylureas, and pyrimidyl-oxy-benzoates. We examined ihibitory activities of newly synthesized triazolopyrimidine sulfonamide derivatives using partially purified ALS from barley. $IC_{50}$ values for the active derivatives are 0.5nM∼8$\mu$M. Among them TP1 and TP2 are the most potent ALS inhibitors with $IC_{50}$ values of 0.5nM and 1.6nM, respectively. These inhibitors are more potent in the inhibition of barley ALS than commercial herbicides, Metosulam ($IC_{50}$;3.6 nM), Flumetsulam ($IC_{50}$;126 nM), and Cadre ($IC_{50};4 {\mu}M$). The progress curves for inhibition of ALS by TP2 showed that the amount of inhibition increases with time. The inhibition of ALS by TP2 was mixed-type inhibition with respect to pyruvate. Dual inhibition analyses of TP2 versus an imidazolinone, Cadre, and Leu showed parallel and intercepting kinetic pattern, respectively. The results suggest that TP2 binds to ALS competively with Cadre but not with Leu. Chemical modification of cysteinly residues in ALS decreased the sensitivity of ALS to Leu, while the modification did not affect the sensitivity of ALS to TP2 and Cadre.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.455-462
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• 2020

Leuconostoc mesenteroides CJNU 0705 was isolated from a breast milk sample and identified by 16S rRNA gene sequencing and confirmed by its ability to produce dextran from tryptic soy agar plates supplemented with 2% sucrose. This strain can absorb various heavy metals including lead (Pb) and cadmium (Cd) which are both found in fine dust and have been shown to be harmful to human skin. In addition, Leu. mesenteroides CJNU 0705 has demonstrated antimicrobial activity against Propionibacterium acnes, the primary causative agent of acne. Given these traits it was natural to evaluate the use of this strain in the fermentation of several natural extracts from green tea, carrot, annual wormwood, parsley, broccoli, and corn silk, which are known to improve skin health, to see if it could increase their dextran content when supplemented with no sucrose, 2% sucrose, or 2% sucrose and 3% yeast extract. The extracts supplemented with both yeast and sucrose were found to produce the most dextran, which was confirmed by the scanning electron microscope (SEM) images. These results suggest that Leu. mesenteroides CJNU 0705 and its fermented natural extracts could be used as functional materials for improving human skin health.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1459-1464
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• 2004

The purpose of this research was to investigate the potential use of cheese whey protein (CWP), a cheese by-product. The physiological activity of calcium-binding peptides in CWP may be used as a food additive that prevents bone disorders. This research also examined the characteristics of calcium-binding peptides. After the CWP was heat treated, it was hydrolyzed by trypsin. Then calcium-binding peptides were separated and purified by ion-exchange chromatography and reverse phase HPLC, respectively. To examine the characteristics of the purified calcium-binding peptides, amino acid composition and amino acid sequence were analyzed. Calcium-binding peptides with a small molecular weight of about 1.4 to 3.4 kDa were identified in the fraction that was flowed out from 0.25 M NaCl step gradient by ion-exchange chromatography of tryptic hydrolysates. The results of the amino acid analysis revealed that glutamic acid in a calcium-binding site took up most part of the amino acids including a quantity of proline, leucine and lysine. The amino acid sequence of calcium-binding peptides showed Phe-Leu-Asp-Asp-Asp-Leu-Thr-Asp and Ile-Leu-Asp-Lys from $\alpha$-LA and Ile-Pro-Ala-Val-Phe-Lys and Val-Tyr-Val-Glu-Glu-Leu-Lys from ${\beta}$-LG.

• Biomedical Science Letters
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• v.10 no.3
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• pp.179-186
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• 2004

We examined a role of proteasome, the non-lysosomal multicatalytic protease complex,on the differentiation of chick embryonic myoblasts in culture. The peptide hydrolyzing activities of proteasome were found to change; the hydrolyzing activity against N-succinyl-Leu-Leu- Val- Tyr-7 -amido-4-methy1coumarin (SLLVY-AMC) was prominent and increased with myogenic differentiation. Proteasome inhibitors, N-carbobenzoxy-Leu-Leu-norvalinal (MG115) and N-carbobenzoxy-Ile-Glu (O-t-butyl)-Ala-Leucinal (PSI), blocked membrane fusion of myoblasts as well as the SLLVY-AMC hydrolyzing activity. Those inhibitory activities of the agents occurred in parallel, but were reversible and both cell fusion and the peptidase activity were restored when the agents were withdrawn from the culture medium. On the other hand, the agents caused accumulation of the ubiquitinylated proteins in the cytoskeletal proteins. These results suggest that each of the peptide hydrolyzing activities of proteasome is independently regulated during the myogenic differentiation and the chymotrypsin-like activity may play an important role in that process.

• Journal of Microbiology and Biotechnology
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• v.7 no.3
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• pp.180-188
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• 1997

Bacillus subtilis C9 was selected by measuring the oil film-collapsing activity and produced biosurfactant in a medium containing glucose as a sole carbon source. The biosurfactant emulsified hydrocarbons, vegetable oils and crude oil, and lowered the surface tension of culture broth to 28 dyne/cm. A biosurfactant, C9-BS produced by B. subtilis C9 was purified by ultrafiltration, extraction with chloroform and methanol, adsorption chromatography, and preparative reversed phase HPLC. Structural analyses, IR spectroscopy, FAB mass spectroscopy, amino acid composition, and NMR analyses, demonstrated that C9-BS was a lipopeptide comprising a fatty acid tail and peptide moiety. The lipophilic part consisting of $C_{14}\;or\;C_{15}$ hydroxy fatty acid was linked to the hydrophilic peptide part, which contained seven amino acids (Glu-Leu-Leu-Val-Asp-Leu-Leu) with a lactone linkage.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.131-135
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• 2015

Two new bitter-tasting cyclic peptides comprising six amino acids, namely gamakamide C and D, were isolated from cultured oysters Crassostrea gigas. Dimethylaminoazobenzene sulfonyl-amino acid analysis detected Val and Leu in gamakamide C and Ile and Leu in gamakamide D. The molecular formula of gamakamide C was determined as $C_{43}H_{60}N_{7}O_8S$ by high-resolution fast atom bombardment mass spectroscopy (HR FAB-MS) ($[M+H]^+m/z822.4200{\Delta}-2.4mmu$), and that of gamakamide D was determined as $C_{43}H_{62}N_7O_8S$ by HR FAB-MS ($[M+H]^+m/z836.4379{\Delta}-2.0mmu$). Comparison of amino acid analyses and fragment ions by MS/MS among gamakamide C, D, and E (known), the structures of gamakamide C and D were confirmed $as-{\small{L}}-Val-{\small{L}}-Met(SO)-{\small{L}}-NMe-Phe-{\small{L}}-Leu-{\small{D}}-Lys-{\small{L}}-Phe-$ and $-{\small{L}}-Ile-{\small{L}}-Met(SO)-{\small{L}}-NMe-Phe-{\small{L}}-Leu-{\small{D}}-Lys-{\small{L}}-Phe-$, respectively.

• Applied Biological Chemistry
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• v.34 no.3
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• pp.265-272
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• 1991

In order to utilize fish skin effectively, the acid-soluble collagen was extracted from the skin of filefish, Novoden modestrus, and the filefish skin collagen(FSG) was modified by papain-catalyzed incorporation of L-leucine alkyl ester(Leu-OCn). The functional properties of an enzymatically modified collagen were measured. The $FSC-Leu-OC_8$ showed very good emulsifiability and foamability and was suitable for use as a low-fat content proteinaceous surfactant.