• Korean Journal of Microbiology
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• v.31 no.1
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• pp.54-62
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• 1993

Intracellular adenosine deaminase (ADA) from Aspergillus oryzae was purified using ammonium sulfate fractionation, a DEAE-Sephadex A-50 anion exchange chromatography, an ultrafiltration using a PM 10 membrane and two times of Sephadex G-100 gel filtration chromatography. The enzyme was purified 151 fold with a 9% recovery. Purified enzyme gave a single protein band with a molecular weight of 105,000 delton. The enzyme was reasonably stable. The enzyme activity was kept even after 1 hr incubation at 55.deg.C, but decreased significantly at 60.deg.C. The pH optimum was found to be from 6.5 to 7.5. Among tested compounds, the substrate activity was found with adenosine, adenine arainofuranoside, formymcin A, 2'-deoxyadenosine, 3'-deoxyadenosine, 2', 3'-isopropylidene adenosine, 2,6-diaminopurine deoxyriboside, .betha.-nicotinamide adenine dinucleotide (reduced form), 6-chloropurine riboside, 2'-adenine monophosphate (AMP), 3'-AMP and 5'-AMP. The values of Km of adenosine and 2'-deoxyadenosine were calculated to be 500 and .$710\mu$m, respectively. ADA was sensitivite to $Zn^{2+}$, $^Cu{2+}$ and $Fe^{3+}$, p-chloromercuribenzoate and mersalyl acid inactivated the enzyme. The activity of enzyme was not changed when ADA was incubated with dithiothreititol, 2-mercaptoethanol, N-ethylmaleimide, iodoacetic acid and iodoacetamide.

• Archives of Pharmacal Research
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• v.28 no.7
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• pp.810-815
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• 2005

Previously, we have shown that astrocytes deprived of glucose became highly vulnerable to peroxynitrite, and adenosine and its metabolites attenuated the gliotoxicity via the preservation of cellular ATP level. Here, we found that adenosine and related metabolites prevented the disruption of mitochondrial transmembrane potential (MTP) in glucose-deprived rat primary astrocytes exposed to 3-morpholinosydnonimine (SIN-1), a peroxynitrite releasing agent. Exposure to glucose deprivation and SIN-1(2h) significantly disrupted MTP in astrocytes, and adenosine prevented it in dose-dependent manner with an $EC_{50}\;of\;5.08{\mu}M$. Adenosine also partially prevented the cell death by myxothiazol, a well-known inhibitor of mitochondrial respiration. Blockade of adenosine deamination or intracellular transport with erythro-9-(-hydroxy-3-nonyl)adenosine (EHNA) or S-(4-nitrobenzyl)-6-thioinosine (NBTI), respectively, completely reversed the protective effect of adenosine. Other purine nucleos(t)ides including inosine, guanosine, ATP, ADP, AMP, ITP, and GTP also showed similar protective effects. This study indicates that adenosine and related purine nucleos(t)ides may protect astrocytes from peroxynitrite-induced mitochondrial dysfunction.

• Korean Journal of Microbiology
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• v.25 no.1
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• pp.46-51
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• 1987

In order to increase the production of tryptophan by maximizing expression of recombinant trp plasmid, Klebsiella pneumoniae KC 105(pheA tyrA trpE trpR tyrR) was genetically modified. KC 107, inosine monophospate(IMP) auxotroph from KC 105 and KC 108, histidine(His) auxotroph from KC 107 were also derived respectively to increase phosphoribosylpyrophosphate(PRPP) production which is required for tryptophan biosynthesis. From KC 107 phosphoribosylpyrophosphate consumption which is required for tryptophan biosynthesis. From KC 107 and KC 108, KC 109 and KC 110, both arginine auxotrophs were derived respectively. To investigate the expression of recombinant trp plasmid in the selected K. pneumoniae mutants, the auxotrophic mutants were transformed with recombinant trp plasmids pSC 101-$trpE^{FBR}$, pSC 101-trpL(.DELTA.att) $trpE^{FBR}$ (pSC 101-trp-AF). Amount of tryptophan produced and activities of tryptophan synthase of $trpR^{-}$ mutant (KC 100) and $tyrR^{-}$ mutnat(KC 105) containing recombinant plasmid pSC 101-trp operon were increased by 30-40% as compared with KC 99(pheA tyrA trpE) containing recombinant plasmid pSC 101-trp operon. Activities of tryptophan synthase and production of tryptophan of KC 108 ($His^{-}$) and KC 109($Arg^{-}$) containing recombinant plasmid pSC 101-trp operon were increase by two-fold as compared with KC 107 containing pSC 101-trp operon.

• Preventive Nutrition and Food Science
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• v.1 no.1
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• pp.16-22
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• 1996

Amino acids and ribonucleotides were measured for boiled-dried anchovy to determine the effect of 5 kGy γ-irradiation on its quality stability during storage at ambient and cooling (5∼10℃) temperatures for 12 months in a laminated-film package(Polyethylene 10㎛). The anchovy samples contained about 55%(d.b) of total amino acids and about 1%(d.b) of free amino acids. Although there found a significant change(p<0.01) in the content of leucine and lysine immediately sfter irradiation, the overall content of toral amino acids was little changed in stored anchovy even six months after irradiation at cooling conditions. γ-Irradiation caused a significant reduction(p<0.01) in the total content of free amino acids, showing a similar tendency by storage conditions. However, the ribonucleotides. which were 12.00mg/g(d.b) in inosine-5'-monophosphate and 0.38mg/g(d.b) in guanosine-5'-monophospate, were resistant to 5kGy-irradiation. With the lapse of storage time, it was also shown that storage temperature was more influential than irradiation on the contents of amino acids and taste compounds of dried anchovy.

• Food Science of Animal Resources
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• v.38 no.6
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• pp.1305-1314
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• 2018

To investigate relationships of electronic taste-traits with muscle fiber type composition (FTC) and contents of nucleotides, porcine longissimus lumborum (LL), psoas major (PM), and infra spinam (IS) muscles were obtained from eight castrated LYD pigs. FTC and taste-traits in these three porcine muscles were measured by histochemical analysis and electronic tongue system, respectively. IS had significantly higher proportion of type I fibers while LL had significantly higher proportion of type IIB than other muscles (p<0.05). IS had the highest inosine monophosphate (IMP) content while LL had the lowest IMP content (p<0.05). In contrast, LL had significantly higher hypoxanthine content compared to PM and IS (both p<0.05). For taste-traits, IS had significantly higher umami and richness values but lower sourness value than LL and PM (p<0.05). Sourness and astringency values of LL were significantly higher than those of IS (p<0.05). The proportion of type IIB fiber was positively correlated with sourness and astringency but negatively correlated with saltiness. These results suggest that sourness and astringency tastes are increased with increasing proportions of type IIB fibers in porcine muscles due to increase of hypoxanthine content. These results also imply that umami and richness tastes are increased with increasing contents of type I and IIA fibers because of increased IMP content in porcine muscles.

• Parasites, Hosts and Diseases
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• v.56 no.6
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• pp.553-558
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• 2018

Pathogenic Acanthamoeba spp. cause granulomatous amoebic encephalitis and keratitis. Acanthamoeba keratitis (AK) is a rare but serious ocular infection that can result in permanent visual impairment or blindness. However, pathogenic factors of AK remain unclear and treatment for AK is arduous. Expression levels of proteins secreted into extracellular space were compared between A. castellanii pathogenic (ACP) and non-pathogenic strains. Two-dimensional polyacrylamide gel electrophoresis revealed 123 differentially expressed proteins, including 34 increased proteins, 7 qualitative increased proteins, 65 decreased proteins, and 17 qualitative decreased proteins in ACP strain. Twenty protein spots with greater than 5-fold increase in ACP strain were analyzed by liquid chromatography triple quadrupole mass spectrometry. These proteins showed similarity each to inosine-uridine preferring nucleoside hydrolase, carboxylesterase, oxygen-dependent choline dehydrogenase, periplasmic-binding protein proteinases and hypothetical proteins. These proteins expressed higher in ACP may provide some information to understand pathogenicity of Acanthamoeba.

• IMMUNE NETWORK
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• v.7 no.1
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• pp.31-38
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• 2007

Background: Mizoribine (MZR) is an imidazole nucleoside isolated from Eupenicillium brefeldianum. MZR is currendy in clinical use for patients who have undergone renal transplantation. Therapeutic efficacy of MZR has also been demonstrated in rheumatoid arthritis and lupus nephritis. MZR has been shown to inhibit the proliferation or lymphocytes by interfering with inosine monophosphate dehydrogenase. Since the exact mechanism by which MZR benefits rheumatoid arthritis (RA) is not clear, we investigated the ability of MZR to direct its immunosuppressive influences on other antigen presenting cells, such as macrophages. Methods: Mouse macrophage RAW264.7 cells were stimulated with lipopolysaccharide in the presence of MZR. To elucidate the mechanism of the therapeutic efficacy in chronic inflammatory diseases, we examined the effects of MZR on the production of pro-inflammatory cytokines, nitric oxide (NO) and prostaglandin $E_2\;(PGE_2)$ in macrophages. Results: MZR dose-dependendy decreased the production of nitric oxide and pro- inflammatory cytokines such as tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), interleukins $1{\beta}$ (IL-${\beta}$ and IL-6 $PGE_2$. Examination of gene expression levels showed that the anti-inflammatory effect correlated with the down-regulation of inducible nitiric oxide synthase expression, cycloxygenase-2 expression and TNF-${\alpha}$ gene expression. Conclusion: In this work, we resulted whether MZR $(1.25{\sim}10{\mu}g/ml)$ inhibited macrophage activation by inhibiting secretion of pro-inflammatory cytokines, NO and $PGE_2$. These findings provide an explanation for the therapeutic efficacy of MZR in chronic inflammation-associated diseases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.625-633
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• 1994

In this study, processing of dried products of adcidian , Haocynthia roretzi, were investigated, which has been cultured in the south and east coast of Korea in recent years. Raw ascidians were shucked , gutted, soaked and then drained. Seven kinds of dried ascidian meats were prepared : boiled in 5% slat solution for 10 min and hot-air dried (A)-sun dried (B) or hot-air dried (C) after soaking for 1 min in 0.2% NaHSO3 solution , sun dried (D) or hot -air dried (G) after treating for 15 sec in 5% liquid smoke solution, and sun dried (E) or hot -air dried (F) after blanching for 30 sec in boiling 5% salt solution added with 0.2% NaHSO3. The moisture contents, water activity of the products showed little change and VBN gradually increased during storage at 25 $\pm$2$^{\circ}C$. The TBA and POV values of the liquid smoked dried ascidian (product D, G0 were considerably lower than those of others, In fatty acid composition 22 : 6 , 20 : 5 : 16: 0 and 18 : 1 acid were predominant. Conditions adopted in products D and G had a good antioxidative effect on highly unsatuated fatty acids during the storage. The contents of inosine and AMP of products were higher than those of other nucleotide and their related compounds. Judging from the results of chemical experiments and sensory evaluation, the sample A, D and G were most desirable and they could be preserved more than 120 days at room temperature(25$\pm$2$^{\circ}C$).

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.7
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• pp.1026-1030
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• 2011

An experiment was conducted to determine the effects of caponization on the muscle composition, ATP-related compounds, the shear values, the taste panel scores and the muscle fiber areas of Taiwan country chicken cockerels. At 10 wks of age, cockerels were divided into two groups: caponized and untreated. Birds were fed grower and finisher diets ad libitum in an eighteen-week experimental period. Results showed that capons contained significantly greater muscle fat content, less breast and thigh muscle moisture content, shear value and muscle fiber area (p<0.05) than those of intact birds. However, neither treatment groups differed significantly (p>0.05) in breast and thigh muscle protein content. Compared with the intact birds, the capons contained significantly (p<0.05) less muscle ash content in the breasts, but did not differ significantly (p>0.05) in thigh muscle ash content. The breast muscle IMP and ATP+ADP+AMP+IMP contents in the intact birds were significantly (p<0.05) higher than those in the capons. The intact birds had significantly (p<0.05) higher ATP and AMP contents than did the capons as well as significantly (p<0.05) less ADP and inosine (HxR) contents in the thigh and breast muscles. The Hypoxanthine (Hx) content of the thighs in the intact birds was significantly (p<0.05) higher than that in the capons; however, there was an adverse effect on the breast muscle Hx content. The breast muscle K value in the intact birds was significantly (p<0.05) lower than that in the capons. The capons produced significantly (p<0.05) higher taste panel scores than did the intact birds for both flavor and juiciness of thigh muscle as well as for flavor and tenderness of breast muscle.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.1038-1046
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• 2013

With the aim of investigating the differences in the quality traits between Korean native chicken (Hanhyup, KNC) and broilers commonly used in two different traditional Korean cuisines, the chemical composition and sensory properties of breast and thigh meat from the two chicken strains were assessed. KNC for baeksuk (chicken meat braised in soup with various Oriental medicinal plants; KNL), KNC for samgyetang (similar to baeksuk but young chickens and ginseng are used; KNS), broiler for baeksuk (BL), and broiler for samgyetang (BS) were used as treatments in this study. KNL and KNS contained higher protein but lower fat content than BL and BS. The $L^*$ values of breast and thigh meat, but not the $a^*$ values, were significantly different between KNS and BS, whereas significant differences in both values were observed between KNL and BL. Compared to the other three types of chickens, KNS contained the highest total and insoluble collagen content, and KNL and BL showed higher inosine-5'-monophosphate content in their meat. Overall, KNL and KNS contributed darker, less tender meat with higher protein and less fat content together with more n-3 fatty acids, as opposed to their counterparts used for the same cuisines. Based on the results of the sensory analysis, even though there are some differences in physiochemical traits, different chicken sources do not differ in overall sensory quality. This information can help consumers to understand better the meat available for their preferred traditional cuisines.