• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.469-474
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• 2001

The actinomycete strain AMLK-335 was antagonistic to vancomycin-resistant enterococci (VRE). Based on the diaminopimelic acid (DAP) type, and morphological and physiological characteristics revealed by scanning electron microscopy (SEM), AMLK-335 was confirmed to belong to the genus Streptomyces. Analysis of the 16S rDNA nucleotide sequences found AMLK-335 to have a relationship with Streptomyces platensis. The production of antibiotic from this strain was most favorable when cultured on glucose, polypeptone, yeast extract (PY) medium for 6 days at $27^{\circ}$. The antibiotic was identified as cyclo(L-phenylalanyl-L-prolyl) by comparing ti with the reported MS and NMR spectral data. Cyclo(phe-pro) from the PY cultures of AMLK-335 was most effective (K-98-258). Futhermore, cyclo(phe-pro) had antimicrobial activity against Bacillus subtilis, Microcuccs luteus, Staphylococcus aureus, and Saccharomyces cerevisiae, but it wa ineffective against Candida albicans, Streptomyces murinus, and Aspergillus niger.

• Journal of Microbiology and Biotechnology
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• v.20 no.2
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• pp.294-300
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• 2010

The Iro protein is a member of the HiPIP family with the [$Fe_4S_4$] cluster for electron transfer. Many reports proposed that the conserved aromatic residues might be responsible for the stability of the iron-sulfur cluster in HiPIP. In this study, Tyr10 was found to be a critical residue for the stability of the [$Fe_4S_4$] cluster, according to site-directed mutagenesis results. Tyr10, Phe26, and Phe48 were essential for the stability of the [$Fe_4S_4$] cluster under acidic condition. Trp44 was not involved in the stability of the [$Fe_4S_4$] cluster. Molecular structure modeling for the mutant Tyr10 proteins revealed that the aromatic group of Tyr10 may form a hydrophobic barrier to protect the [$Fe_4S_4$] cluster from solvent.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8605-8611
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• 2016

The reliability of using diagnostic binary ratios of particulate carcinogenic polycyclic aromatic hydrocarbons (PAHs) as chemical tracers for source characterisation was assessed by collecting PM10 samples from various air quality observatory sites in Thailand. The major objectives of this research were to evaluate the effects of day and night on the alterations of six different PAH diagnostic binary ratios: An/(An + Phe), Fluo/(Fluo + Pyr), B[a]A/(B[a]A + Chry), B[a]P/(B[a]P + B[e]P), Ind/(Ind + B[g,h,i]P), and B[k]F/Ind, and to investigate the impacts of site-specific conditions on the alterations of PAH diagnostic binary ratios by applying the concept of the coefficient of divergence (COD). No significant differences between day and night were found for any of the diagnostic binary ratios of PAHs, which indicates that the photodecomposition process is of minor importance in terms of PAH reduction. Interestingly, comparatively high values of COD for An/(An + Phe) in PM10 collected from sites with heavy traffic and in residential zones underline the influence of heterogeneous reactions triggered by oxidising gaseous species from vehicular exhausts. Therefore, special attention must be paid when interpreting the data of these diagnostic binary ratios, particularly for cases of low-molecular-weight PAHs.

• Journal of Environmental Science International
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• v.15 no.5
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• pp.397-403
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• 2006

Compositional characteristics and origin of polycyclic aromatic hydrocarbons(PAHs), which should be strongly regulated for environmental protection in the crude oils and petroleum products, have been investigated by gas chromatography-mass spectrometry(GC/MS). In the crude oils analyzed, two-rings compound(naphthalene) of PAHs was detected around $72.3\sim93.5%$, but five- or six-rings compound of PAHs was not detected. In the crude oils analyzed, the molecular ratio indices of Phe/Ant(phenanthrene/anthracene)>15, Fla/Pyr(fluoranthene/pyrene)<1, BaA/Chr(benzo (a)anthracene/chrysene)$\leq0.4$ could be effectively applied, and we found that the origin of PAHs was petrogenic sources. Total PAHs concentrations in the crude oils were increased with increasing API gravity and with decreasing sulfur contents of the analyzed crude oils. Five- or six-rings compound of PAHs were not included in ail petroleum products except bunker-C. Furthermore, the molecular ratio indices of Phe/Ant(phenanthrene/anthracene) vs. Fla/Pyr(fluoranthene/pyrene) could be effectively applied as the standard for the PAHs contamination criterion at the other Korean areas.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.679-682
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• 2002

Energy dissipations in a general PHE flow are the compounded effects of the piled corrugate geometries and its wall pressure and temperature distributions. In addition, although the exchangers are substantial pieces of engineering equipment, they are composed of a very large number of nominally identical and small geometrical elements. In the present numerical study, the three-dimensionally complicated energy dissipation fields and those wall-shape-induced flow destabilization are investigated in the cross-corrugated passages, which result in high energy transports with comparatively low pressure drop. We revealed the critical conditions as $Re=157.3 for the wall-shape-induced flow destabilization in a general PHE element by initial value method, or shooting method, and compare its value to that of analytical solution of plane Poiseille flow, two-dimensional grooved flow and so on. We also observed the detailed variation of flow field and energy transportation with changes in time and flow variables such as Reynolds number. Lastly, we considered the flow natural frequency, or Strouhal number, with variation of hydrodynamic conditions for the best use of active control, such as forced mass flow rate pulsative flow, to enhance energy transportation.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.1
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• pp.61-64
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• 2000

A series of 5-oxaproline peptide derivatives was synthesized and evaluated for its ability to inhibit the prolyl 4-hydroxylase in vitro. Structure-activity studies show that the 5-oxaproline sequences, prepared by the 1,3-dipolar cycloaddition of the C-methoxycarbonyl-N-mannosyl nitrone in the presence of the ethylene, are more active than the corresponding proline derivatives. Prolyl 4-hydroxylase belongs to a family of $Fe^{2+}-dependent$ dioxygenase, which catalyzes the formation of 4-hydroxyproline in collagens by the hydroxylation of proline residues in -Gly-Xaa-Pro-Gly- of procollagen chains. In this paper we discover the more selective N-Cbz-Gly-Phe-Pro-Gly-OEt $(K_m\;=\;520\;{\mu}M)$ sequences which are showed stronger binding than others in vitro. Therefore, we set out to investigate constrained tetrapeptide that was designed to mimic the proline structure of pep tides for the development of prolyl 4-hydroxylase inhibitor. From this result, we found that the most potent inhibitor is N-Dansyl-Gly-Phe-5-oxaPro-Gly-OEt $(K_i\;=\;1.6\;{\mu}M)$. This has prompted attempts to develop drugs which inhibit collagen synthesis. Prolyl 4-hydroxylase would seem a particularly suitable target for antifibrotic therapy.

• BMB Reports
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• v.37 no.5
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• pp.597-602
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• 2004

N-terminal His-tagged recombinant $\beta$-1,4-galactosyltransferase from Neisseria meningitidis was expressed and purified to homogeneity by column chromatography using Ni-NTA resin. Mutations were introduced to investigate the roles of, Ser68, His69, Glu88, Asp90, and Tyr156, which are components of a highly conserved region in recombinant $\beta$-1,4 galactosyltransferase. Also, the functions of three other cysteine residues, Cys65, Cys139, and Cys205, were investigated using site-directed mutagenesis to determine the location of the disulfide bond and the role of the sulfhydryl groups. Purified mutant galactosyltransferases, His69Phe, Glu88Gln and Asp90Asn completely shut down wild-type galactosyltransferase activity (1-3%). Also, Ser68Ala showed much lower activity than wild-type galactosyltransferase (19%). However, only the substitution of Tyr156Phe resulted in a slight reduction in galactosyltransferase activity (90%). The enzyme was found to remain active when the cysteine residues at positions 139 and 205 were replaced separately with serine. However, enzyme reactivity was found to be markedly reduced when Cys65 was replaced with serine (27%). These results indicate that conserved amino acids such as Cys65, Ser68, His69, Glu88, and Asp90 may be involved in the binding of substrates or in the catalysis of the galactosyltransferase reaction.

• BMB Reports
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• v.46 no.6
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• pp.295-304
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• 2013

Extracellular acidification occurs not only in pathological conditions such as inflammation and brain ischemia, but also in normal physiological conditions such as synaptic transmission. Acid-sensing ion channels (ASICs) can detect a broad range of physiological pH changes during pathological and synaptic cellular activities. ASICs are voltage-independent, proton-gated cation channels widely expressed throughout the central and peripheral nervous system. Activation of ASICs is involved in pain perception, synaptic plasticity, learning and memory, fear, ischemic neuronal injury, seizure termination, neuronal degeneration, and mechanosensation. Therefore, ASICs emerge as potential therapeutic targets for manipulating pain and neurological diseases. The activity of these channels can be regulated by many factors such as lactate, $Zn^{2+}$, and Phe-Met-Arg-Phe amide (FMRFamide)-like neuropeptides by interacting with the channel's large extracellular loop. ASICs are also modulated by G protein-coupled receptors such as CB1 cannabinoid receptors and 5-$HT_2$. This review focuses on the physiological roles of ASICs and the molecular mechanisms by which these channels are regulated.

• Journal of the Korean Society of Costume
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• v.27
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• pp.121-132
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• 1996

This study showed the proper pigment extract in the Phe. Dyeing which is the basic dye of the natural plants dyeing,. Also it compared and examined the K/S the promotion of the color fastness and the effect of color difference change were attended by mordants and method of mordanting. 1. The most absorbance of Phellodendron. sol-ution is 330nm berberine is 430nm. 2. The best and proper temperature to extrat Phe,. was 80 and dyeing solution for 24 hours. 3. The pH effect was stable in the absorbances and color differences change. 4. Mordanted group increased the absorbances compared to non-mordanted sample. In case depth the most absorbance of Al. Sn. K. Cu and C. A solution were in 3% Fe and Cr were in 5%. In the color difference change they became dark reduced greenish and increased yellowish when their absorbances were in 3% 5. K./S was recoginzed by tainnin and fe, K/S was more increased pre-mordants than post-mordants. 6. Fe is the unchangable mordant in the color difference change and pre-mordants is more stable than post-mordants in the difference color. 7. Generally light C. F indicated more than grade 2 and light C. F, was much improved in post-mordanted by alumium potassium potass-ium dichromate. Washing C.F was improved in mordanted by tainnin and ferrous suulfate mordanted group was better than non-mordanted sample. Perspir-ation C,F was more stable in acid than alkali. Dry cleaning C.F indicated more than grade. 4.

• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.563-568
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• 2010

The Val289 residue in the $\alpha$-amylase of Bacillus amyloliquefaciens, which is equivalent to the Ala289 and Val286 residues in the $\alpha$-amylases of B. stearothermophilus and B. licheniformis, respectively, was studied by site-directed mutagenesis. This residue was substituted with 10 different amino acids by random substitution of the Val codon. In these mutant $\alpha$-amylases, Val289 was substituted with Ile, Tyr, Phe, Leu, Gly, Pro, Ser, Arg, Glu, and Asp. Compared with the wild-type $\alpha$-amylase, the mutant $\alpha$-amylase Val289Ile showed 20% more hydrolytic activity, whereas Val289Phe and Val289Leu showed 50% lesser activity. On the other hand, the mutant $\alpha$-amylases Val289Gly, Val289Tyr, Val289Ser, and Val289Pro showed less than 15% activity. The substitution of Val289 with Arg, Asp, or Glu resulted in complete loss of the $\alpha$-amylase activity. Interestingly, the mutant $\alpha$-amylase Val289Tyr had acquired a transglycosylation activity, which resulted in the change of product profile of the reaction, giving a longer oligosaccharide.