• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1708-1716
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• 2016

Glucose dehydrogenase (GDH) is an oxidoreductase enzyme and is used as a biocatalyst to regenerate NAD(P)H in reductase-mediated chiral synthesis reactions. In this study, the glucose 1-dehydrogenase B gene (gdhB) was cloned from Bacillus thuringiensis subsp. kurstaki, and wild-type (GDH-BT^WT) and His-tagged (GDH-BT^N-His, GDH-BT^C-His) enzymes were produced in Escherichia coli BL21 (DE3). All enzymes were produced in the soluble forms from E. coli. GDH-BT^WT and GDH-BT^N-His showed high specific enzymatic activities of 6.6 U/mg and 5.5 U/mg, respectively, whereas GDH-BT^C-His showed a very low specific enzymatic activity of 0.020 U/mg. These results suggest that the intact C-terminal carboxyl group is important for GDH-BT activity. GDH-BT^WT was stable up to 65℃, whereas GDH-BT^N-His and GDH-BT^C-His were stable up to 45℃. Gel permeation chromatography showed that GDH-BT^WT is a dimer, whereas GDH-BT^N-His and GDH-BT^C-His are monomeric. These results suggest that the intact N- and C-termini are required for GDH-BT to maintain thermostability and to form its dimer structure. The homology model of the GDH-BT^WT single subunit was constructed based on the crystal structure of Bacillus megaterium GDH (PDB ID 3AY6), showing that GDH-BT^WT has a Rossmann fold structure with its N- and C-termini located on the subunit surface, which suggests that His-tagging affected the native dimer structure. GDH-BT^WT and GDH-BT^N-His regenerated NADPH in a yeast reductase-mediated chiral synthesis reaction, suggesting that these enzymes can be used as catalysts in fine-chemical and pharmaceutical industries.

• 대한바이러스학회지
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• 제26권1호
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• pp.9-22
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• 1996

Respiratory Syncytial virus (RSV) is an important cause of acute lower respiratory tract infections in human, with infants and young children being particularly susceptible. In the temperate zones, sharp annual outbreaks of RSV occur during the colder months, in both the northern and the southern hemisphere. RSV is unusual in that it can repeatedly reinfect individuals throughout life and infect babies in the presence of maternal antibody. RSV isolates can be divided into two subgroups, A and B, on the basis of their reactions with monoclonal antibodies, and the two subgroups are also distinct at the nucleotide sequence level. The specific diagnosis of RSV infection was best made by isolation of virus in tissue culture, identification of viral antigen, or by specific serologic procedures. Recently, rapid detection of RSV and analysis of RSV strain variation became possible by development of methods of reverse transcription and polymerase chain reaction amplification. In this study, to determine the genetic diversity of RSV found in Korea, 173 bp and 164 bp spanning selected regions of the RSV F and SH genes were enzymatically amplified and sequenced, respectively. Eight for F gene and three for SH gene were detected in 66 nasopharyngeal swap samples tested. Two major antigenic subgroups, A and B were confirmed from Korean samples (seven for subgroup A and one for subgroup B). At the nucleotide level of the F gene region, Korean subgroup A strains showed 95-99% homologies compared to the prototype A2 strain of subgroup A and 93-100% homologies among Korean subgroup A themselves. For the SH gene region, Korean subgroup A strain showed 97.5% homology compared to the prototype A2 strain of subgroup A, and Korean subgroup B strain showed 97% homology compared to the prototype 18537 strain of subgroup B. Most of base changes were transition and occured in codon position 3, which resulted in amino acid conservation. Using the maximum parsimony method, phylogenetic analysis indicated that Korean RSV strains formed a group with other RSV strains isolated from the United States, Canada, the Great Britain and Australia.

• 미생물학회지
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• 제30권1호
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• pp.53-59
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• 1992

자연계로부터 4-chlorobiphenyl (4CB) 을 분해하는 P08, P20, 027 그리고 P1242 균주를 불리하였다. 이들 분해 균주들의 4CB 분해 과정을 UV-spectrophotometry 방법으로 분석한 결과, 4-CB 로 부터 2-hydroxy-6-oxo-6-(4'-chlorophenyl)hexa-2, 4-dienoic acid 와 4-chlorobenzoate(4CBA) 가 생성되었다. 따라서 분해균주들은 공통적으로 meta-cleavage pathway에 의하여 4CB 를 분해하는 것으로 확인되었다. 그러나 DJ-12, P08 그리고 P27 균주는 4CBA 를 계속 분해하여 4-hydroxybenzoate 를 생성하였으나, P20 과 P1242 균주들은 4CBA 를 더이상 분해하지 못 하였다. 각 분해 균주에서 cbp 유전자군의 상동성을 분석하기 위하여 P. pseudoalcaligenes KF707 의 bphABC 유전자군을 DNA probe 로 이용하여 Southern hybridization 을 실시한 결과, DJ-12, P08 그리고 P27 균주들은 XhoI 에 의한 2.2kb 와 1.8 kb, 그리고 EcoRI 에 의한 11 kb 의 genomic DNA 의 절편에서 hybridization 이 일어났다. 따라서 본 연구에서 분리한 4CB 분해 균주들의 cbp 유전자군은 분해경로 및 bph 유전자군과의 상동성에 의거하여 부 group 으로 구분되었다.

• 한국균학회지
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• 제27권1호통권88호
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• pp.39-43
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• 1999

불로초의 계통 분류학적 조사를 위해 불로초속 중 8종(Ganoderma lucidum, G. tsugae, G. pfeifferi, G. resinaceum, G. australe-applanatum, G. oregonense, G. neo-japonicum, G. applanatum) 12균주와 out-group 균주로는 Inonotus xeranticus의 rDNA ITS II를 PCR로 증폭하여 염기서열을 비교 조사하였다. 불로초 속 중 ITS II 영역의 길이는 $247{\sim}257\;bp$로 분포하였고 종간 상동성은$70{\sim}100%$ 로 조사되었다. 계통도를 분석한 결과는 5개의 군(cluster)을 형성하였고 G. tsugae는 각각의 G. lucidum과 하나의 clade를 이루어 두 종은 서로 매우 밀접하게 진화된 것으로 사료되었다. 본 조사에서는 국내에서 재배되고 있는 불로초(G. lucidum)는 그 발생지 및 국외 ITS염기서얼 자료와 비교 및 분석할 때 G. tsugae로 하는 것이 타당할 것으로 사료되었다.

• 한국균학회지
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• 제38권1호
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• pp.40-47
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• 2010

Phytophthora 속의 핵(ypt 유전자, rDNA-IGS region) 및 미토콘드리아(Cox 유전자, $\beta$-tubline 유전자, EF1A 유전자) 내에 존재하는 5가지 유전자 영역을 이용하여 국내 Phytophthora 속 14종의 유전적 다양성을 분석하였다. 국내 Phytophthora 속은 외국의 Phytophthora 속과 동일한 clade를 형성하였으나, 외국의 Phytophthora 속과 마찬가지로 본 연구에서도 분자생물학적 분류와 형태학적 분류와는 연관성을 찾기 어려웠다. 기존에 보고된 국내 P. palmivora KACC 40167 균주의 그룹이 국내에서 보고된 분류체계와 일치하지 않아 추후 재검토가 필요하였다. P. cryptogea-P. drechsleri complex group 내 국내 P. cryptogea KACC 40161 균주와 P. drechsleri KACC 40195 균주는 서로 94% 이상의 유사도를 보여 재동정이 필요하였으며, P. parasitica와 P. nicotianae간의 유사도가 99% 이상으로 나타나 이 두 종간에 통일된 종명이 요구된다. 또한 현재 분자계통학상 5그룹으로 구분된 국내 Phytophthora 속을 외국균주들과 비교하여 10개의 그룹으로 새롭게 재분류하였다. 이러한 결과들은 국내 Phytophthora 속의 유전적 다양성 연구를 위해 유용한 자료가 될 것이다.

• 생명과학회지
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• 제20권12호
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• pp.1743-1749
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• 2010

Edwardsiella tarda는 그람 음성의 장내세균과의 주요 어병세균으로 어류에 edwardsiellosis를 유발하는 전신감염성 병원체이다. 최근 병원성 세균의 외막 단백질들은 세균성 감염에 있어서 숙주와 반응하여 면역반응을 유도하는 것으로 여겨져 연구가 되고 있다. 일본의 연구팀은 어류에서 에드워드병의 원인체인 E. tarda의 37 kDa 단백질이 넙치에서 높은 항원성을 제시하는 것을 보고하였다. 또한 그 연구자들은 37 kDa 단백질의 N-말단 아미노산 서열이 GAPDH와 대응하는 것을 밝혔다. 본 연구에서는 다른 세균에서 알려진 N-말단 서열을 기반으로 primer를 제작하여 이에 상응하는 E. tarda DNA를 증폭하고 클로닝하였다. 이 DNA단편의 염기서열은 예상한 바와 같이 세균의 GAPDH유전자인 gapA와 높은 상동성이 있고, E. tarda GAPDH (etGAPDH)의 아미노산 서열은 다른 장내세균의 GAPDH와 70% 이상의 상동성을 보이는 것을 확인하였다. E. tarda의 외막단백질에 특이적으로 반응하는 항체를 이용하여 E. tarda의 GAPDH가 외막에 존재한다는 것을 증명하였고, gapA의 염기서열을 바탕으로하여 재조합 GAPDH를 과발현 시켰다. 과발현된 재조합단백질 GAPDH는 GAPDH 특이적인 항체를 제조하는데 사용되었고, 또한 넙치에 면역시켜 단일 단백질 백신으로서의 활용도를 모색하였다. 비록 재조합 GAPDH가 면역된 넙치에서 GAPDH에 특이적인 항체가 증가하였음에도 불구하고, E. tarda로 공격실험을 하였을 때 면역된 넙치의 생존율이 12.5%로 측정되어 면역된 그룹과 면역되지 않은 그룹간에 큰 차이가 없는 것이 확인되었다.

• Journal of Animal Science and Technology
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• 제47권3호
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• pp.317-324
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• 2005

A method for sex determination of pigs was examined using polymerase chain reaction(PCR). Sex determining region Y(SRY) gene encoded on Y chromosome plays a key role for primary male development. Zinc finger X-Y(ZFX-ZFY) gene, one of the X-V homology gene group was found on the X and Y chromosomes, respectively, We tested for molecular sexing by amplification patterns of SRY and ZF genes. Genomic DNAs from various resources including porcine hairs and semen collected from domestic pig breeds and native pigs was used for PCR assay of each gene. The amplified products for porcine SRY gene were yielded only in males but not in females. On the other hand, two differential patterns were observed in amplification of ZF gene reflecting the chromosomal dimorphism by a length polymorphism between X and Y chromosomes. Of both, a common band was detected in all individuals tested so that this band might be amplified from ZFX gene as a PCR template, but another is specific for males indicated that from ZFY. The result of PCR assay provides identical information to that from investigation of phenotypic genders of the pigs tested. We suggest that this PCR strategy to determine porcine sexes using comparison of the amplification patterns of the SRY gene specific for Y chromosome and the dimorphic ZF gene between X and Y chromosomes may be a rapid and precise method for discrimination of two sexes and applied to DNA analysis of small samples such as embryonic blastomere, semen, and hairs.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.544-552
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• 2002

Several microorganisms from rat and human feces and lumen fluid of cows were screened for their ability to decolorize the synthetic dyes. Consequently, a novel dye-degrading strain AB&J was isolated. Taxonomic identification including 165 rDNA sequencing and phylogenetic analysis indicated that the isolate had 99.9% homology in its 165 rDNA base sequence with Clostridium perfringens. After 27 h Incubation with the strain, brilliant blue R, bromophenol blue, crystal violet, malachite green, methyl green, and methyl orange were decolorized by about 69.3%, 97.7%, 96.3%, 97.9%, 75.1%, and 97.2%, respectively. The triphenlmethane dye, bromophenol blue, was decolorized extensively by growing Clostridium perfringens AB&J cells in liquid cultures under anaerobic condition, although their growth was strongly inhibited in the initial stage of incubation. This group of dyes is toxic, depending on the concentration used. The dye was significantly decolorized at a relatively lower concentration of below 50 $\mu g \;ml^{-1}$, however, the growth of the cells was mostly suppressed at a dye concentration of 100 $\mu g \;ml^{-1}$. The decolorization activity in cell-free extracts was much higher in cytoplasm than in periplasm and cytoplasmic membrane. Therefore, the enzyme related uptake of bromophenol blue seemed to be localized in cytoplasm. The optimal pH and temperature of bromophenol blue uptake fur decolorization activities were 7.0 and 4$0^{\circ}C$, respectively.

• Journal of Applied Biological Chemistry
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• 제51권1호
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• pp.1-6
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• 2008

Estrogens, a group of steroid compounds functioning as the primary female sex hormone, play an important role in the development and progression of breast cancer. In this study, using a novel annealing control primer-based GeneFishing PCR technology, five differentially expressed genes (DEGs), expressed using 10nM mitogenic estrogens, $17{\beta}$-estradiol (E2) and $16{\alpha}$-hydroxyestrone ($16{\alpha}$-OHE1), were selected from the estrogen receptor (ER)-positive MCF-7 human breast cancer cells. The DEGs, MRPL42, TUBA1B, SSBP1, KNCT2, and RUVBL1, were identified by comparison with the known genes via direct sequencing and sequence homology search in BLAST. Quantitative real-time PCR data showed that two DEGs, tubulin ${\alpha}1b$ and kinetochore associated 2, were greater than 2-fold upregulated by E2 or $16{\alpha}$-OHE1. Both genes could be new biomarkers for the treatment and prognosis of cancers, and further study may provide insights into the molecular mechanisms underlying development and progression of breast cancer.

• Journal of Microbiology and Biotechnology
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• 제14권5호
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• pp.959-966
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• 2004

Twenty-three cultures of harmful algal bloom (HAB)-(causing dinoflagellates were isolated from the coastal waters of Korea. For each of the 14 morphospecies, the nuclearencoded small subunit (SSU) rDNA was analyzed to determine the phylogenetic relatedness of the species. Despite temporal and spatial isolation, 3-4 clonal cultures of Alexandrium catenella, Cochlodinium polykrikoides, and Gymnodinium catenatum had 100% identical SSU rDNA sequences. In contrast, heterogeneities in the SSU rDNA sequences were observed in Akashiwo sanguinea and Lingulodinium polyedrum strains. Extreme sequence polymorphism was shown within the SSU rRNA genes of an Al. tamarense clonal culture. A homology search in GenBank revealed that 11 dinoflagellate species were located in clusters corresponding to their morphological classification. The SSU rDNA sequences of C. polykrikoides, Gyrodinium instriatum, and Pheopolykrikos hartmannii, which were determined for the first time in this study, showed the following phylogenetic relationships: C. polykrikoides formed an independent branch separated from other dinoflagellates; Gyr. instriatum was placed in a monophyletic group with Gyr. dorsum and Gyr. uncatenum; and Ph. hartmanii, which forms a distinct two-celled pseudocolony, belonged to Gymnodinium sensu Hansen and Moestrup.