• Microbiology and Biotechnology Letters
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• v.10 no.3
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• pp.177-184
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• 1982

Studies were carried out to investigate the optimal culture conditions for the production of penicillinase using a strain of Streptomyces sp. isolated from soil, YS-40. Among the carbon and nitrogen sources, glucose and L-asparagine increased the peniciilinase production. The addition of M $n^{＋＋}$, $Ca^{＋＋}$ and L $i^{＋}$ increased the enzyme production, but depressed by F $e^{＋＋＋}$, F $e^{＋＋}$, $Mg^{＋＋}$, Z $n^{＋＋}$, A $g^{＋＋}$, $Ba^{＋＋}$ and S $n^{＋＋}$. L-Leucine slightly increased the enzyme production but L-histidine, L-methionine depressed. Among the vitamins riboflavine, i-inositol, hesperidine, niacin-amide, biotin, folic acid, DL-$\alpha$-lipoic acid increased the enzyme formation. The addition of cephradine, cephalexin, ampicillin, cloxacillin more increased the enzyme formation than that of other$\beta$-lactam antibiotics and antibiotics. Optimal pH and temperature on the enzyme formation was pH 7.0 and 28$^{\circ}C$ respectively Amount of the enzyme production reached at maximum with incubation for 3 days on the optimal condition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.5
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• pp.786-790
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• 1996

The changes in chemical constituents of onion in Korea and the degree of hydrolysis in onion by-drolysates by treatment of viscozyme L, celluclast 1.5L, pectinex and cereflo were investigated. Proximate compositions of onion in Korea were as follows; The contents of moisture, protein, lipid, carbohydrate and ash were 89~90%, 1.8~1.9%, 0.4~0.5%, 7.1~8.5% and 0.3~0.5%, respectively. Major free sugars were identified to be glucose, fructose and sucrose and major free amino acids were as cysteine, histidine, arginine and glutamic acid. The degree of hydrolysis by treatment of viscozyme L, celluclast 1.5L, pectinex and cereflo was 69%, 71%, 80% and 62%, respectively. During the enzymatic hydrolysis, free sugar and total sugar content increased however, pyruvic acid content decreased significantly.

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.29-36
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• 2007

The xynA gene encoding the xylanase A of Paenibacillus sp. DG-22 was isolated with a DNA probe obtained by PCR amplification, using degenerated primers deduced from the amino acid residues of the known N-terminal region of the purified enzyme and the conserved region in the family 11 xylanases. The positive clones were screened on the LB agar plates supplemented with xylan, by the Congo-red staining method. The xynA gene consists of a 630-bp open reading frame encoding a protein of 210 amino acids, and the XynA preprotein contains a 28-residues signal peptide whose cleavage yields a l82-residues mature protein of a calculated molecular weight of 20,000Da and pI value of 8.77. The cloned DNA fragment also has another ORF of 873 nucleotides that showed 76% identity to the putative transcriptional activator of Bacillus halodurans C-125. Most of the xylanase activity was found in the periplasmic space of E. coli. The xynA gene was subcloned into pQE60 expression vector to fuse with six histidine-tag. The recombinant xylanase A was purified by heating and immobilized metal affinity chromatography. The optimum pH and temperature of the purified enzyme were 6.0 and $60^{\circ}C$, respectively. This histidine-tagged xylanase A was less thermostable than the native enzyme.

• Nutritional Sciences
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• v.9 no.2
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• pp.106-111
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• 2006

Chronic alcohol consumption is associated with perturbation of hepatic metabolism of sulphur-containing amino acid. The goal of present study was to evaluate the influence of dietary supplementation of methionine or folate to chronically ethanol-fed mts on the metabolism of sulfur-containing amino acids and one-carbon metabolism. Sprague-Dawley male mts were fed Lieber-Decarli liquid diet with 0% ethanol (control), 36% ethanol (E), 36% ethanol combined with methionine supplement (EM) or folate supplement (EF) for 8 weeks. Hepatic S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH), plasma folate and homocysteine (Hcy), urinary excretion of folate and formiminoglutamate were investigated after feeding experimental diets. Growth was retarded by 36% ethanol consupmtion (E, EM and EF) (p<0.01). Liver total fat (p<0.05) and plasma ALT (P<0.01) were increased by methionine supplementation (EM), implicating fatty liver and liver injury. Liver folate was increased slightly by folate supplementation (EF) (p=0.077). Urinary folate loss was increased 2.3 fold by ethanol consumption (E) and 17.2 fold by folate supplementation (EF), while decreased by methionine supplementation (EM) (p<0.000l). Plasma Hcy was increased 1.9 fold by methionine supplementation (EM) in ethanol-fed mts (p<0.05), which was related with decreased methionine synthase activity (p<0.05). Hepatic SAM/SAH ratio was depressed by methionine supplementation in ethanol-fed mts (EM) (p<0.05). Urinary formininoglutamate (Figlu) excretion after histidine loading was increased by ethanol ingestion and reduced by methionine supplementation (p<0.00l). Based on these data, methionine supplementation appears to accelerate histidine oxidation. In conclusion, dietary supplementation of methionine to ethanol-fed mts exacerbates alcoholic liver injury possibly by complicating sulphur-containing amino acid metabolism, as while it may have beneficial effects on folate and histidine metabolism.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.487-493
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• 1986

Lactobacillus helveticus YM-1and Streptococcus lactis Ml$_3$ were inoculated together in reconstituted non-fat skim milk medium, and then their proteolytic activity and stimulatory compound for acid production were investigated. Significant difference between Lactobacillus helveticus YM-1 and Streptococcus lactis Ml$_3$was observed in the proteolytic activities. The proteolytic activity of Lactobacillus helveticus YM-1 and Streptococcus lactis Ml$_3$ was 105 $\mu\textrm{g}$/$m{\ell}$ and 30 $\mu\textrm{g}$/$m{\ell}$ when converted the amounts of hydrolysates of milk protein determined by Folin Ciocaleau phenol method into their tyrosine equivalent Stimulatory compounds in cell-free filtrate of Lactobacillus helveticus YM-1were identified as peptide with a molecular weight of approximately 4, 300 for the acid production by Streptococcus lactis Ml$_3$. Some kinds of amino acids, such as histidine, lysine, arginine and glutamic acid, were rich in acid hydrolysates of peptide. Among amino acids, histidine, glutamic acid and phenylalanine stimulated acid production, on the contrary isoleucine inhibited.

• BMB Reports
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• v.32 no.4
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• pp.358-362
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• 1999

dTDP-D-glucose 4,6-dehydratase as an oxidoreductase catalyzes the conversion of dTDP-D-glucose to dTDP-4-keto-6-deoxy-D-glucose, which is essential for the formation of 6-deoxysugars. dTDP-D-glucose 4,6-dehydratase shows remarkable sterochemical convergence in which displacement of the C-6 hydroxyl group by a C-4 hydrogen proceeds intramolecularly with inversion of configuration. The reaction mechanism is known to be oxidation, dehydration, and reduction by bases mediating proton transfer and $NAD^+$ cofactor. In this study, the bases in the active site domain are proposed to be His-79 and His-300 from a comparison of the peptides of the dehydratase and UDP-D-glucose epimerase. His-79 and His-300 were mutated to prepare the mutants H79L (mutation of histidine to leucine at the 79th amino acid) and H300A (mutation of histidine to alanine at the 300th amino acid) by site-directed mutagenesis. The H79L protein was inactive, showing that His-79 participates in the reaction mechanism.

• Journal of Life Science
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• v.6 no.4
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• pp.241-249
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• 1996

A collagenase was isolated from the culture filtrate of Vibrio mimicus (ATCC 33658). The enzyme was purified to homogeneity by ammonium sulfate precipitation and DEAE-Sephadex A-50 chromatography, which an activity recovery of 22%. The molecular weight of the purified enzyme was estimated to be 42 kDa by SDS-polyacrylamide gel electrophoresis and gel filtration, indication a monomer structure. The optimum pH and temperature od the enzyme for insoluble collagen (Type I) were around 7.75 and 28$\circ$C, respectively. Some chelating agents and serine protease inhibitor inactivated the enzyme, but L-cysteine and histidine did not affect the activity. The amino acid composition indicated that the collagenase contained high amounts of amino acid residues of glycine and alanine. The K$_{m}$ and R$_{cat}$/K$_{m}$ values for the collagenase, using insoluble collagen (type I) as substrate, were 2.86 mg/ml and 972.28 U/mg-protein, respectively.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.719-721
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• 2009

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.701-708
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• 1996

To evaluate the possibility of using a by-products of skipjack canning as a food or feedstuff, the proximate composition, total and free amino acids, total lipid composition, and nucleotide related compounds were analyzed. The crude protein was highest in dark muscle, while lipid was highest in head. The important total amino acids in by-products were founded to be glycine, glutamic acid, alanine and histidine. The important free amino acids from dark muscle and head were taurine, histidine and anserine. The amounts of histidine, anserine and carnosine in dark muscle was higher than those of cooking drips, head, and raw vicera. The major fatty acids in by-products were palmitic, stearic, oleic and docosahexaenoic acid (DHA). The inosine and hypoxanthine were important nucleotide related compounds in by-products. The results suggests that by-products from skipjack can be used as food sources and feedstuffs especially for marine fish culture.

• The Journal of Natural Sciences
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• v.5 no.1
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• pp.53-57
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• 1992

This experiment was carried out to elucidate some kinetic properties of the $\alpha$-galactosidase which produced and purified from Aspergillus niger ATCC 16513 and soybean(Glycine max. L). The Km value of Asp. niger and soybean $\alpha$-galactosidase were 37.0mM and 50.0mM for raffinose and55.5mM and 55.5mM for stachyose, respectively. The activity of Asp. niger and soybean $\alpha$-galactosidase were inhibited by galactose. Among the amino acids in active sites of both Asp. niger and soybean $\alpha$-galactosidase, histidine was identified by chemical modification of diethyl pyrocarbonate. Number of amino acids residues per mole of Asp. niger and soybean $\alpha$-galactosidase were 902 and 286, respectively.