• Title/Summary/Keyword: ${\alpha}$-amino acids

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Immunomodulating Activity of Fungal ${\beta}-Glucan$ through Dectin-1 and Toll-like Receptor on Murine Macrophage

  • Kim, Ha-Won
    • 한국약용작물학회:학술대회논문집
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    • 2006.11a
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    • pp.103-115
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    • 2006
  • [ ${\beta}-Glucan$ ] is a glucose polymer that has linkage of ${\beta}-(1,3)$, -(1,4) and -(1,6). As exclusively found in fungal and bacterial cell wall, not in animal, ${\beta}-glucans$ are recognized by innate immune system. Dendritic cells (DC) or macrophages possesses pattern recognition molecule (PRM) for binding ${\beta}-glucans$ as pathogen-associated molecular pattern (PAMP). Recently ${\beta}-glucans$ receptor was cloned from DC and named as dectin-l which belongs to type II C-type lectin family. Human dectin-l is consisted of 7 exons and 6 introns. The polypeptide of dectin-l has 247 amino acids and has cytoplasmic, transmembrane, stalk and carbohydrate recognition domains. Dectin-l could recognize variety of beta-l,3 and/or beta-l,6 glucan linkages, but not alpha-glucans. In our macrophage cell line culture system, dectin-l mRNA was detected in RA W264.7 cells by reverse transcription-polymerase chain reaction (RT-PCR). Dectin-l was also detected in the murine organs of spleen, thymus, lung and intestines. Treatment of RA W264.7 cells with ${\beta}-glucans$ of Ganoderma lucidum (GLG) resulted in increased expression of IL-6 and $TNF-{\alpha}$ in the presence of LPS. However, GLG alone did not increase IL-6 nor $TNF-{\alpha}$ These results suggest that receptor dectin-l cooperate with CD14 to activate signal transduction that is very critical in immunoresponse.

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Novel Fabrication of Designed Silica Structures Inspired by Silicatein-a

  • Park, Ji-Hun;Kwon, Sun-Bum;Lee, Hee-Seung;Choi, In-Sung S.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.557-557
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    • 2012
  • Silicatein-${\alpha}$, the enzyme extracted from silica spicules in glass sponges, has been studied extensively in the way of chemistry from 1999, in which the pioneering work by Morse, D. E. - the discovery of the enzymatic hydrolysis in Silicatein-${\alpha}$ - was published. Since its reaction conditions are physiologically favored, synthesis of various materials, such as gallium oxide, zirconium oxide, and silicon oxide, was achieved without any hazardous wastes. Although some groups synthesized oxide films and particles, they have not achieved yet controlled morphogenesis in the reaction conditions mentioned above. With the knowledge of catalytic triad involved in hydrolysis of silicone alkoxide and oligomerization of silicic acid, we designed the novel peptide amphiphiles to not only form self-assembled structure, but also display similar activities to silicatein-${\alpha}$. Designed templates were able to self-assemble into left-handed helices for the peptide amphiphiles with L-form amino acid, catalyzing polycondensation of silicic acids onto the surface of them. It led to the formation of silica helices with 30-50 nm diameters. These results were characterized by various techniques, including SEM, TEM, and STEM. Given the situation that nano-bio-technology, the bio-applicable technology in nanometer scale, has been attracting considerable attention; this result could be applied to the latest applications in biotechnology, such as biosensors, lab-on-a-chip, biocompatible nanodevices.

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Reaction of Potassium Fluoride with Orgarnic Halogen Compound-II. Dimerization, Fluorination, and Decarboxylation of Organic Iodo acids, Iodides, and Polychlorinated Acid Ester (有機할로겐化合物과 KF 과의 反應 (第2報) 有機요-드酸, 沃化物 及 多鹽素化有機酸, 에스텔의 雙合, 弗化 及 脫炭酸 反應에 關하여)

  • Kim, You-Sun
    • Journal of the Korean Chemical Society
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    • v.8 no.4
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    • pp.135-141
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    • 1964
  • The reaction of potassium fluoride with amyl iodide in presence of dimethylformamide at low temperature gave a fluorination product together with decane. Polyhalogenated acid such as ${\alpha}$, ${\beta}$,-dichloro-${\beta}$-phenyl-propionic acid gave ${\alpha}$-chlorostyrene, fluorinated styrene, and fluorinated acid. The same reaction with the ethyl ester did not give the fluorination product and gave a mixture of various dimerized product. Dibromostyrene gave bromostyrene together with fluorination product. Iodo acid such as m-iodo acid gave the salt and a trace quantity of dimerized product. Iodides such as m-iodotoluene and 1-amino-4-iodo-2-methyl benzene did not show any appreciable reactivity towards potassim fluoride. The reaction condition was described, and fluorination, ${\alpa}$-dehydrofluorination, decarboxylation, and dimerization were discussed.

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The Taste Compounds of Damchi-jeotguk -Concentrated Sea Mussel Extract- (담치젓국의 정미성분(呈味成分))

  • Lee, Eung-Ho;Ahn, Chang-Bum;Oh, Kwang-Soo;Kim, Jin-Soo;Jee, Sung-Kil;Kim, Jeong-Gyun
    • Journal of the Korean Society of Food Culture
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    • v.2 no.1
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    • pp.25-31
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    • 1987
  • We have examined to evaluate the taste compounds of damchi-jeotguk(concentrated sea mussel extract) which is a kind of traditional processed sea food in Korea. The contents of such compounds as free amino acids, nucleotides their and related compounds, non-volatile organic acid and fatty acid composition were analyzed. The content of total free amino acids was 10520.5mg/100g on dry basis and the major ones were glycine, arginine, aspartic acid and glutamic acid. These amino acids were resulted as 55.7% of total free amino acids in damchi-jeotguk. Hypoxanthine was the highest content($8.77\;{\mu}mole/g$, dry basis) of nucleotides and their related compounds. Free amino acid-N was the most abundant, resulting 53.3% of extractive nitrogen which was 3490.2mg/100g on dry basis and next ammonia-N, nucleotide-N and TMAO-N in order. The major non-volatile organic in damchi-jeotguk were succinic acid(125.5mg/100g, dry basis) and lactic acid 91.9mg/100g, dry basis). In this fatty acid composition of total lipid, polyenoic acid was abundant holding 45.5%. The major fatty acids were 16 : 0, 18 : 2, 22 : 6, 18 : 1 and 20 : 5. It was concluded from the omission test and chemical analysis that the major taste compounds of damchi-jeotguk were free amino acids and non-volatile organic acids.

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Evaluating Nutritional Quality of Single Stage- and Two Stage-fermented Soybean Meal

  • Chen, C.C.;Shih, Y.C.;Chiou, P.W.S.;Yu, B.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.5
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    • pp.598-606
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    • 2010
  • This study investigated the nutritional quality of soybean meal (SBM) fermented by Aspergillus ($FSBM_A$) and/or followed by Lactobacillus fermentation ($FSBM_{A+L}$). Both fermented products significantly improved protein utilization of SBM with higher trichloroacetic acid (TCA) soluble true protein content, in vitro protein digestibility and available lysine content, especially in $FSBM_{A+L}$. Moreover, $FSBM_{A+L}$ produced a huge amount of lactic acid resulting in lower pH as compared to the unfermented SBM or soybean protein concentrate (SPC) (p<0.05). $FSBM_A$ and $FSBM_{A+L}$ raised 4.14% and 9.04% of essential amino acids and 5.38% and 9.37% of non-essential amino acids content, respectively. The ${\alpha}$-galactoside linkage oligosaccharides such as raffinose and stachyose content in $FSBM_A$ and $FSBM_{A+L}$ decreased significantly. The results of soluble protein fractions and distribution showed that the ratio of small protein fractions (<16 kDa) were 42.6% and 63.5% for $FSBM_A$ and $FSBM_{A+L}$, respectively, as compared to 7.2% for SBM, where the ratio of large size fractions (>55 kDa, mainly ${\beta}$-conglycinin) decreased to 9.4%, 5.4% and increased to 38.8%, respectively. There were no significant differences in ileal protein digestibility regardless of treatment groups. SPC inclusion in the diet showed a better protein digestibility than the SBM diet. In summary, soybean meal fermented by Aspergillus, especially through the consequent Lactobacillus fermentation, could increase the nutritional value as compared with unfermented SBM and is compatible with SPC.

Functional Identification and Expression of Indole-3-Pyruvate Decarboxylase from Paenibacillus polymyxa E681

  • Phi, Quyet-Tien;Park, Yu-Mi;Ryu, Choong-Min;Park, Seung-Hwan;Ghim, Sa-Youl
    • Journal of Microbiology and Biotechnology
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    • v.18 no.7
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    • pp.1235-1244
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    • 2008
  • Indole-3-acetic acid (IAA) is produced commonly by plants and many bacteria, however, little is known about the genetic basis involving the key enzymes of IAA biosynthetic pathways from Bacillus spp. IAA intermediates from the Gram-positive spore-forming bacterium Paenibacillus polymyxa E681 were investigated, which showed the existence of only an indole-3-pyruvic acid (IPA) pathway for IAA biosynthesis from the bacterium. Four open reading frames (ORFs) encoding indole-3-pyruvate decarboxylase-like proteins and putative indole-3-pyruvate decarboxylase (IPDC), a key enzyme in the IPA synthetic pathway, were found on the genome sequence database of P. polymyxa and cloned in Escherichia coli DH5$\alpha$. One of the ORFs, PP2_01257, was assigned as probable indole-3-pyruvate decarboxylase. The ORF consisted of 1,743 nucleotides encoding 581 amino acids with a deduced molecular mass of 63,380 Da. Alignment studies of the deduced amino acid sequence of the ORF with known IPDC sequences revealed conservation of several amino acids in PP2_01257, essential for substrate and cofactor binding. Recombinant protein, gene product of the ORF PP2_01257 from P. polymyxa E681, was expressed in E. coli BL21 (DE3) as a glutathione S-transferase (GST)-fusion protein and purified to homogeneity using affinity chromatography. The molecular mass of the purified enzyme showed about 63 kDa, corresponding closely to the expected molecular mass of IPDC. The indole-3-pyruvate decarboxylase activity of the recombinant protein, detected by HPLC, using IPA substrate in the enzyme reaction confirmed the identity and functionality of the enzyme IPDC from the E681 strain.

Furan in Thermally Processed Foods - A Review

  • Seok, Yun-Jeong;Her, Jae-Young;Kim, Yong-Gun;Kim, Min Yeop;Jeong, Soo Young;Kim, Mina K.;Lee, Jee-yeon;Kim, Cho-il;Yoon, Hae-Jung;Lee, Kwang-Geun
    • Toxicological Research
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    • v.31 no.3
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    • pp.241-253
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    • 2015
  • Furan ($C_4H_4O$) is a volatile compound formed mostly during the thermal processing of foods. The toxicity of furan has been well documented previously, and it was classified as "possible human carcinogen (Group 2B)" by the International Agency for Research on Cancer. Various pathways have been reported for the formation of furan, that is, thermal degradation and/or thermal rearrangement of carbohydrates in the presence of amino acids, thermal degradation of certain amino acids, including aspartic acid, threonine, ${\alpha}$-alanine, serine, and cysteine, oxidation of ascorbic acid at higher temperatures, and oxidation of polyunsaturated fatty acids and carotenoids. Owing to the complexity of the formation mechanism, a vast number of studies have been published on monitoring furan in commercial food products and on the potential strategies for reducing furan. Thus, we present a comprehensive review on the current status of commercial food monitoring databases and the possible furan reduction methods. Additionally, we review analytical methods for furan detection and the toxicity of furan.

Molecular Cloning and Sequence Analysis of Human GM3 Synthase (hST3Gal V)

  • Kim, Kyung-Woon;Kim, Kyoung-Sook;Kim, Cheorl-Ho;Kim, June-Ki;Lee, Young-Choon
    • BMB Reports
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    • v.32 no.4
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    • pp.409-413
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    • 1999
  • The cDNA encoding CMP-NeuAc:lactosylceramide ${\alpha}2$,3-sialyltransferase (GM3 synthase) was isolated from a human fetal brain cDNA library using sequence information obtained from amino acid sequences found in the conserved regions of the previously-cloned mouse GM3 synthase (mST3Gal V) and human sialyltransferases. The cDNA sequence included an open reading frame coding for 362 amino acids, and the primary structure of this enzyme predicted all the structural features characteristic of other sialyltransferases, including a type II membrane protein topology and both sialylmotifs. Comparative analysis of this cDNA with mST3Gal V showed 85% and 86% identity of the nucleotide and amino acid residues, respectively. The expression of this gene is highly restricted in both human fetal and adult tissues.

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Hydrolysis of Silk Fibroin on Alkali Conditions (견 피브로인의 알칼리 가수분해)

  • 김남정;배도규
    • Journal of Sericultural and Entomological Science
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    • v.39 no.2
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    • pp.197-202
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    • 1997
  • To hydrolyze silk fibroin was treated with NaOH solution on various concentrations and times. And it was examined that the addition effects of NaHSO3 solution on the solubility and colouring of silk fibroin. As obtained results are as follows; The more increasement of concentration and time of NaOH treatment, the more increasement of solubility but solubility was slight above 3% concentration of NaOH. Fibroin yield was decreased above 3% concentration. This was due to formation of peptide or amino acids below molecular weight 3,000. Most of molecular weight distribution came out to be under 3,000 in 2% concentration and 4hrs of NaOH treatment. The more increasement of adding concentration and 4hrs of NaOH treatment. The more increasement of adding concentration of NaHSO3, the more reduction of solubility but white index of powder increased. In the results of FT-IR spectras of silk fibroin powder obtained by various concentrations of NaHSO3 treatment, the absorbent peak at 3,400 cm-1 which was considered as -CH=N- (azomethine) was disappeared by the more addition of NaHSO3. It showed that absorbent peak of $\beta$-fibroin moved into low temperature region and transferred to $\alpha$- and random coil structure through the DSC experiment. In the results of amino acid analysis, alkali hydrolysis reduced the oxy amino contents acid like serine and tyrosine, but increased the glycine content by the more addition of NaHSO3.

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Liquid Chromatographic Resolution of Racemic $\alpha$-Amino Acid Derivatives on an Improved $\pi$-Acidic Chiral Stationary Phase Derived from (S)-Leucine

  • 현명호;이승준;류재정
    • Bulletin of the Korean Chemical Society
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    • v.19 no.10
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    • pp.1105-1109
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    • 1998
  • A chiral stationary phase derived from (S)-N-(3,5-dinitrobenzoyl)leucine N-phenyl N-alkyl amide (CSP 2) was applied in separating the two enantiomers of various π-basic aromatic derivatives of leucine N-propyl amide in order to evaluate π-basic aromatic groups as an effective derivatizing group for the resolution of a-amino acids. Subsequently N-(3,5-dimethoxybenzoyl) group was found to be very effective as a π-basic aromatic derivatizing group. Based on these results, N-(3,5-dimethoxybenzoyl) derivatives of various a-amino N-propyl amides, N,N-diethyl amides and esters were resolved on the CSP derived from (S)-N-(3,5-dinitrobenzoyl) leucine N-phenyl N-alkyl amide (CSP 2) and the resolution results were compared with those on the CSP derived from (S)-N-(3,5-dinitrobenzoyl)leucine N-alkyl amide (CSP 1). The enantioselectivities exerted by CSP 2 were much greater than those exerted by CSP 1. In addition, racemic N-(3,5-dimethoxybenzoyl)-a-mino N,Ndiethyl amides were resolved much better than the corresponding N-(3,5-dimethoxybenzoyl)-a-mino N-propyl amides and esters on both CSPs. Based on these results, a chiral recognition mechanism utilizing the π-π donor-acceptor interaction and the two hydrogen bondings between the CSP and the analyte was proposed.