• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.172-175
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• 2002

The complete nucleotide sequence of the nahC gene from Pseudomonas fluorescens, the structural gene for 1,2-dihydroxynaphthalene (1,2-DHN) dioxygenase, was determined. The 1,2-DHN dioxygenase is an extradiol ring-cleavage enzyme that cleaves the first ring of 1,2-dihydroxynaphthalene. The amino acid sequence of the dioxygenase deduced from the nucleotide sequence suggested that the holoenzyme consists of eight identical subunits with a molecular weight of approximately 34,200. The amino acid sequence of 1,2-DHN dioxygenase showed more than $90\%$ homology with those of the dioxygenases of other Pseudomonas strains. However, sequence similarity with those of the Sphingomonas species was less than $60\%$. The nahC gene of P. fluorescens was moderately expressed in E. coli NM522, as determined by enzymatic activity.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.145-149
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• 1995

For the purpose of developing a new biodegradable detergent, we have isolated a gene encoding wide-range temperature applicable alkaline protease from Xanthomonas sp. YL-37 (Lee et al., 1994, Kor. J. Appl. Microbiol. Biotechnol.). An alkaline protease gene was isolated from the gene bank that was prepared from the chromosomal DNA of Xanthomonas sp. YL-37. From the results of agarose gel electrophoresis and a restriction enzyme mapping, a 2.7 kb DNA fragment containing the alkaline protease gene was inserted in the plasmid pUC9. Extracellular activity of a clone having alkaline protease gene was detected on SDS-polyacrylamide gel with activity staining assay. The molecular weight of alkaline protease was determined to be about 64 kDa from 11% SDS-PAGE analysis. Alkaline protease activity, produced from E. coli which harboring the plasmid, showed no difference at reaction temperature 20, 30 and 40$\circ$C, respectively. This result showed that alkaline protease produced from E. coli harboring the plasmid was apparently the same as that of Xanthomonas sp. YL-37.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.5
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• pp.784-792
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• 1990

In this paper, attempts have been made to compare the subjective performance of sub-band coding (SBC) techniques incorporating four representative modulation transfer functions (MTF's) of th human visual system(HVS): Sakrison, Nill, Ngan, and Rao. In SBC, the frequency band of input signal is split into 16 equal sub-bands. In addition, 28 sub-band splitting schemd which splits more sub-bands in low spatial frequency is considered to compare the 4 MTF's effectively. In encoding of each sub-band, the weight of each sub-band obtained from the MTF of HVS is applied to bit allocation process which minimize the weighted mean square error (WMSE). The differential pulse code modulation(DPCM) coder is used to encode the lowest sub-band and the pulse code modulation(PCM) coder is used for the rest of sub-bands. It is found that the images incorporating the MTF of Rao yields the best results in subjective criteria, followed by Ngan, Nill, Sakrison, and the images not employing the HVS.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.6
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• pp.937-943
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• 1990

In this paper, a subband coding scheme using the human visual system(HVS) model for encoding monochrome images is proposed to produce perceptually higher quality images compared with the regular subband coding scheme. The proposed approach first transforms the intensity image to the density image by a point nonlinear transformation. A frequency band dexomposition of the density image is carried out by means of 2-D seaprable quadrature mirror filters, which split the density image spectrum into 16 equall rate subbands. Bits are allocated among the subbands to minimize the weighted mean squar error (WMSE) for differential pulse code modulation(DPCM) coding of the subbands. The weight for each subband is calculated from the modulation transfer function (MTF) of the HVS model at corresponding frequencies. The performances of the proposed approach are evaluated for 256 * 256 monochrome images at the bit rates of 0.5, 0.75 and 1.0 bita per pixel. Computer simulation results indicate that using the HVS model yields more pleasing reconstructed images than regular subband coding approach which does not use HVS model.

• BMB Reports
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• v.34 no.5
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• pp.440-445
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• 2001

Pesticide waste and chemical stockpiles are posing a potential threat to both Vie environment and human health. There is currently a great effort toward developing effective and economical methods for the detoxification of these toxic organophosphates. In terms of safety and economy, enzymatic biodegradation has been recommended as the most promising tool to detoxify these toxic materials. To develop an enzymatic degradation method to detoxify such toxic organophosphorus compounds, a gene encoding organophosphorus acid anhydrolase (OPAA) from genomic DNA of Alteromonas haloplanktis C was subcloned and expressed. The enzyme consists of a single polypeptide chain with a molecular weight of 48 kDa. It demonstrates strong hydrolyzing activity on sarin, an acetylcholinesterase inhibitor. Moreover, its high activity is sustained for a considerable length of time. It is projected that the recombinant OPAA can be applied as an enzymatic tool that can be used not only for the detoxification of pesticide wastes, but also for the demilitarization of chemical stockpiles.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.9
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• pp.1203-1208
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• 2001

Linzhi Native Pig is a unique local breed recently discovered in the hinterland of Tibet. Its geological distribution, natural environment and ecological conditions have been explored. Using random sampling in typical colony of classification and standard animal-scientific and biogenetic techniques, we examined its contour features, size and weight, reproductive performances, carcass characters, meat quality, fresh-keeping features and the frequency distribution in the 19 structural gene loci encoding enzymes and proteins; according to folklores and Tibetan, Chinese and English history books, the materials and literature of Tibetan Studies, we have analyzed its origin and affirmed the fact that its products have been consumed as Tibetan medicine resources. Our findings make certain that Linzhi Native Pig holds great potential value in economy and culture.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.353-356
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• 2004

Rotavirus and Norovirus are major causative agents of acute diarrhea and gastroenteritis. In our study, Each viral RNA was isolated from the feces of patients for viral diarrhea in Korea, respectively. And cDNA library were constructed using RT-PCR. Also, cDNAs encoding VP8 derived from Rotavirus and Capsid protein derived from norovirus were subesequently cloned and expressed in Echerichia coli as a fusion antigen. Molecular weight of fusion antigen was approximately 60kDa. Also, substantial overexpression was accomplished. We yielded egg yolk lgY which is potentially useful in controlling of Rotavirus and Norovirus which are one of the most prevalent pathogenic viruses.

• BMB Reports
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• v.40 no.1
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• pp.65-71
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• 2007

The Helicoverpa armigera nucleopolyhedrovirus (HearNPV) ORF80 (ha80) has 765 bp encoding a protein with approximately 254 amino acids and a predicted molecular weight of 30.8 kDa. Homologues of ha80 are found in most baculovirus sequences, including those from lepidopteran NPVs, lepidopteran granuloviruses (GVs), hymenopteran baculoviruses, and one dipteran baculovirus, yet their functions remain unclear. In this study we characterized ha80, and showed that it was transcribed late in infected host cells (HzAM1). The product of ha80 was a 31 kDa protein that was not a structural protein of budded virus (BV) or occlusion-derived virus (ODV) particles. Ha80 was first detected in the cytoplasm of infected HzAM1 cells at 12 h p.i., and was observed in the nucleus at later stages of infection, suggesting that it may be involved in transporting viral proteins into the host cell nucleus or play its roles in the nucleus.

• Journal of Microbiology
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• v.37 no.4
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• pp.218-223
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• 1999

Legionella pneumophila, the cause of Legionnaires disease, is able to survive intracellularly in eukaryotic cells such as monocytes, macrophages, and protozoan organisms. During protein biosynthesis, the rph gene encodes ribonuclease (RNase) PH which functions as a phosphorolytic nuclease that removes nucleotides following the CCA terminus of tRNA and as a nucleotidyl-transferase which adds nucleotides to the ends of RNA molecules by usingnucelside diohosphates as substrates. In this sutdy, the rph gene was screened in pUC19 library employing a DNA probe which was constructed from PCR based on a consensus pattern of multiple alignment of RNas PH. The encoded protein consists of 235 amino acid residues with a calculated molecular weight of 26,112 Daltons. The RNase PH signature domains are completely conserved.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.31-32
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• 2005

Neoagaro-oligosaccharides are produced only by enzymatic degradation of agarose by ${\beta}-agarase.^{1)}$ Neoagaro-oligosaccharides inhibit the growth of bacteria, slow the rate of degradation of starch, are used as low-calorie additives to improve food quality, and have macrophage-stimulating activity. Furthermore, neoagarobiose is a rare reagent that has both moisturizing effect on skin and whitening effect on melanoma $cells.^{2)}$ An agar-degrading marine bacterium was isolated from the sea water at the northeast coast in Cheju island, Korea. The strain was gram negative, aerobic, and motile rod. The 16S rRNA of the strain had the closest match of 98% homology, with that from Agarivorans albus. On the basis of several phenotypic characters and a phylogenetic analysis, this strain was designated Agarivorans sp. JA-1. In solid agar plate, Agarivorans sp. JA-1 produced a diffusible agarase that caused agar softening around the colonies. Agarivorans sp. JA-1 was cultured for 36 hr in marine broth 2216 (Difco, USA) and the supernatant that containing an extracellular ${\beta}-agarase$ was prepared by centrifugation of culture media. The enzyme exhibited relatively strong activity at $40^{\circ}C$ and was stable up to $60^{\circ}C$. Using PCR primers derived from the ${\beta}-agarase$ gene of Vibrio sp., the gene encoding ${\beta}-agarase$ from Agarivorans sp. JA-1 was cloned and sequenced. The structural gene consists of 2931 bp encoding 976 amino acids with a predicted molecular weight of 107,360 Da. The deduced amino acid sequence showed 99% and 34% homology to $agaA^{2)}$ and $agaB^{2)}$ genes for ${\beta}-agarase$ from Vibrio sp., respectively. The expression plasmid for ${\beta}-agarase$ gene of Agarivorans sp. JA-1 is being constructed and the recombinant enzyme will be biochemically characterized.