• Journal of Microbiology
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• 제35권4호
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• pp.323-326
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• 1997

Toxin protein from Ustilago maydis virus SH14 isolated in Korea was purified using ethanol precipitation, cation exchange, gel filtration and anion exchange chromatography. The molecular weight of the purified protein was estimated to be 8.3 kDa by SDS-PAGE analysis. The Nterminal sequence of the protein is L-G-I-N-C(K)-R-G-S-S-Q--C(K)-G-L-S-G which is highly homologous with that of P4 toxin, but the amino acid composition and electrophoretic mobility in a native PAGE of the toxin protein were totally different from those of P4 toxin respectively. The SH14 toxin was shown to have immunological cross-reactivity about 50% with P4 toxin when examined by Western hybridization.

• Journal of Environmental Health Sciences
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• 제33권2호
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• pp.158-165
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• 2007

본 연구는 근원에 따른 용존 유기물의 특성을 평가하기 위해 하천수, 호소수, 하수 2차 처리 유출수의 자연수 및 Aldrich, Wako 사에서 공급된 휴믹산을 대상으로 분자량 분포에 따른 물리 화학적인 수질 특성, 생분해도, 소독, 부산물의 생성 등을 고찰하였다. SUVA를 이용해서 자연수의 생분해 가능성을 평가한 결과 호소수, 하수, 하천수 순으로 예측되었으며 이는, 실제 생분해도 실험 결과와 유사하였다 생분해 반응 중 저분자 영역대의 용존 유기물은 점차 감소하였고 반면에 고분자 영역대의 용존 유기물은 증가하였다. SMP는 전체 용존 유기물의 0.7-5.5%정도 관찰되었으며 고분자 물질을 많이 함유한 시료에서 높게 나타났다. THM 생성은 대체로 고분자 물질이 높을수록 증가하였으며 THMFP도 Wako 휴믹산을 제외한 샘플에서 이와 유사한 경향을 나타냈다.

• Animal Systematics, Evolution and Diversity
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• 제27권3호
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• pp.213-219
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• 2011

Some echinoids were collected from the coast of Gangwon-do during the period from November 2008 to July 2011 and were identified on the basis of morphological characteristics and molecular analysis of cytochrome oxidase subunit I mitochondrial DNA. Among them, Strongylocentrotus pallidus (Sars, 1871) belonging to the family Strongylocentrotidae of the order Camarodonta is reported for the first time in Korea and is redescribed. The genetic differences ranged from 0.038 to 0.139 between S. pallidus and four other species of genus Strongylocentrotus, but ranged from 0.002 to 0.005 between Korean specimens and GenBank data of S. pallidus. This species is widely distributed in cold sea water along the western part of the North Pacific and the Northwest Atlantic.

• The Korea Journal of Herbology
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• 제22권4호
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• pp.21-28
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• 2007

Objectives : Kyenegum has been popularly used long as the digestive. The purpose of this study was to investigate the purification and characteristics of protease obtained from Kyenegum crude enzyme. Methods : Kyenegum protease was purified by precipitation with ammonium sulfate followed by SP-Spharose ion exchange chromatography. The molecular weight of Kyenegum protease was estimated by SDS-PAGE electrophoresis. Results : Kyenegum protease was 3,087 units/mg protein specific activity, 14.5 purification fold and 9.8 % recovery. The molecular weight of protease was estimated to be 18 kDa. The isoelectric point was pI 8.97 and values of Km and Vmax of its were 48 mg/mL and 2 units/min, respectively. Conclusion : The result suggests that the protease obtained from Kyenegum has excellent stability of temperature, acid and collagen substrate specificity.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.190-194
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• 2004

The structures and complexation energies of penta-O-tert-butyl ester 1 of p-tert-butylcalix[5]arene toward a series of alkyl ammonium guests have been optimized by ab initio HF/6-31G method. The calculated complexation efficiencies of 1 for alkyl ammonium guests have been found to be similar to the values of previously reported debutylated-calix[5]arene 2. Calculation results show that both of the calix[5]aryl derivatives have much better complexation ability toward ammonium cation without alkyl group over other alkyl ammonium guests. The structural characteristics of the calculated complexes are discussed as a function of the nature of the alkyl substituents of the ammonium guests.

• Proceedings of the KIEE Conference
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.304-306
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• 1991

A new gas-flow type reactor for plasma polymerization was developed to symthesize functional polymer, which enhances the reaction of radicals activated in discharge. $\alpha$-Methylstyrene was used for the polymerization, which are known as starting monomers for the polymer with degradating characteristics. The molecular structure and molecular weight distribution of the polymers were studied.

• Proceedings of the Korean Society of Life Science Conference
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• 한국생명과학회 2001년도 제34회 학술심포지움
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• pp.21-28
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• 2001

A newly isolated Aspergillus niger possessing the novel epoxide hydrolase(EHase) activity was investigated for the enantioselective hydrolysis of racemic aromatic epoxides. The gene encoding EHase was cloned by RT-PCR, and molecular characteristics of the EHase gene were compared with other microbial EHases. The cloned gene encodes 398 amino acids with a deduced molecular mass of 44.5 kDa and pI of 4.83, and sequence homology with other microbial EHase was low. Functional recombinant EHase could be obtained by heterologous expressions in E. coli. Enantioselectivity of recombinant EHase was tested for valuable aromatic epoxide intermediates. Reaction conditions of EHase-catalyzed asymmetric resolution were optimized for the production of chiral styrene oxide.

• BMB Reports
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• 제29권3호
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• pp.248-252
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• 1996

The epidermal organ of the leech contains a complex glycoprotein molecule of mucus. The mucus excreted from annelids plays Significant role in protection against desiccation and parasites. Mucus from the Korean native leech, H. nipponia, was investigated for biochemical characteristics for possible development of biomaterials of cosmetic and pharmaceutical agents. The leech skin mucus was heavily glycosylated mucin-like protein with a high molecular weight comprised 80% carbohydrate and 20% protein. Threonine, serine, and glycine were the major components of the isolated protein and these accounted for 50% of total amino acids. The carbohydrate portion contained glucosamine, galactosamine. galactose, glucose. mannose and sialic acid in oligosaccharide form linked with threonine and serine residues of the glycoprotein.

• BMB Reports
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• 제30권3호
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• pp.216-221
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• 1997

Changes in pathogenicity of old and successively-cultured isolates of Fusarium oxysporum f. sp. niveum have been observed and the concept that such cultures will become attenuated is generally accepted. However, the genetic basis for this phenomenon has not been studied. In an effort to identify a DNA marker closely linked to variations, DNA methylation was investigated both before and after the successive transfers of F. o. f. sp. niveum isolates on artificial media. A sector of mycelium in F. o. f. sp. niveum race 2 isolate (TXXID) which showed variation in pigmentation and colonial morphology occurred after 18 successive weekly transfers on potato dextrose agar (PDA). The sector characteristics were stable and did not change after more successive transfers. It was shown that DNA methylation preexists in ribosomal RNA gene (rDNA) of F. o. f. sp. niveum and that additional changes in DNA methylation occurred during successive culturing.

• Proceedings of the KSME Conference
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• 대한기계학회 2004년도 추계학술대회
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• pp.1086-1091
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• 2004

The boundary layer is a very important characteristic of a liquid-vapor interface since it governs the heat and mass transfer phenomena across an interface. However, the thickness of a boundary layer is generally micro- or nano-sized, which requires highly accurate measurement devices and, consequently, costs the related experiments very high and time-consuming. Due to these size dependent limitations, the experiments related with a nano-scaled size have suffered from the errors and the reliability of the obtained data. This study is performed to grasp the characteristics of a liquid-vapor interface, by using a molecular dynamics method. The simulation results were compared with other studies if possible. Although other studies reported that there existed a temperature discontinuity over an interface when the system was reduced to micro- or nano-sized, we confirmed that there was no such a temperature discontinuity.