• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.216-225
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• 2020

An esterase gene, estA1, was cloned from Alteromonas sp. 39-G1 isolated from the Beaufort Sea. The gene is composed of 1,140 nucleotides and codes for a 41,190 Da protein containing 379 amino acids. As a result of a BLAST search, the protein sequence of esterase EstA1 was found to be identical to Alteromonas sp. esterase (GenBank: PHS53692). As far as we know, no research on this enzyme has yet been conducted. Phylogenetic analysis showed that esterase EstA1 was a member of the bacterial lipolytic enzyme family IV (hormone sensitive lipases). Two deletion mutants (Δ20 and Δ54) of the esterase EstA1 were produced in Escherichia coli BL21 (DE3) cells with part of the N-terminal of the protein removed and His-tag attached to the C-terminal. These enzymes exhibited the highest activity toward p-nitrophenyl (pNP) acetate (C₂) and had little or no activity towards pNP-esters with acyl chains longer than C₆. Their optimum temperature and pH of the catalytic activity were 45℃ and pH 8.0, respectively. As the NaCl concentration increased, their enzyme activities continued to increase and the highest enzyme activities were measured in 5 M NaCl. These enzymes were found to be stable for up to 8 h in the concentration of 3-5 M NaCl. Moreover, they have been found to be stable for various metal ions, detergents and organic solvents. These salt-tolerant and chemical-resistant properties suggest that the enzyme esterase EstA1 is both academically and industrially useful.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 춘계학술대회
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• pp.187-187
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• 2003

Methylmercury (MeHg), one of the heavy metal compounds, can cause severe damage to the central nervous system in humans. Many reports have shown that MeHg is poisonous to human body through contaminated foods and has released into the environment. Despite many studies on the pathogenesis of MeHg-induced central neuropathy, no useful mechanism of toxicity has been established so far. In this study, two methods, cDNA Microarray and SSH, were performed to assess the expression profile against MeHg and to identify differentially expressed genes by MeHg in neuroblastoma cell line. TwinChip Human-8K (Digital Genomics) was used with total RNA from SH-SY5Y (human neuroblastoma cell line) treated with solvent (DMSO) and 6.25 uM (IC50) MeHg. And we performed forward and reverse SSH method on mRNA derived from SH-SY5Y treated with DMSO and MeHg (6.25 uM). Differentially expressed cDNA clones were sequenced and were screened by dot blot and ribonuclease protection assay to confirm that individual clones indeed represent differentially expressed genes. These sequences were identified by BLAST homology search to known genes or expressed sequence tags (ESTs). Analysis of these sequences may provide an insight into the biological effects of MeHg in the pathogenesis of neurodegenerative disease and a possibility to develop more efficient and exact monitoring system of heavy metals as environmental pollutants.

• Journal of Microbiology and Biotechnology
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• 제8권4호
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• pp.378-387
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• 1998

The DNA sequence immediately following the xynA gene of Bacillus stearothermophilus 236 ［about l-kb region downstream from the translational termination codon (TAA) of the xynA gene］was found to have an ability to enhance the xylanase activity of the upstream xynA gene. An 849-bp ORF was identified in the downstream region, and the ORF was confirmed to encode a novel protein of 283 amino acids designated as XaiF (xylanase-activity-increasing factor). From the nucleotide sequence of the xaiF gene, the molecular mass and pI of XaiF were deduced to be 32,006 Da and 4.46, respectively. XaiF was overproduced in the E. coli cells from the cloned xaiF gene by using the T7 expression system. The transcriptional initiation site was determined by primer extension analysis and the putative promoter and ribosome binding regions were also identified. Blast search showed that the xaiF and its protein product had no homology with any gene nor any protein reported so far. Also, in B. subtilis, the xaiF trans-activated the xylanase activity at the same rate as in E. coli. In contrast, xaiF had no activating effect on the co-expressed ${\beta}-xylosidase$ of the xylA gene derived from the same strain of B. stearothermophilus. In addition, the intracellular and extracellular fractions from the E. coli cells carrying the plasmid-borne xaiF gene did not increase the isolated xylanase activity, indicating that the protein-protein interaction between XynA and XaiF was not a causative event for the xylanase activating effect of the xaiF gene.

• 한국균학회지
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• 제44권1호
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• pp.1-7
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• 2016

우리나라 토양에서 효모 종 분포특성을 조사하기 위해 먼저 대전광역시를 포함하는 충청남도 전 지역의 밭 토양 61점을 2015년 6월부터 8월까지 수집하여 97균주 20종의 야생효모들을 분리하였고, polymerase chain reaction (PCR)을 통해 internal transcribed spacer (ITS) 부위와 26S rDNA의 D1/D2 부위의 염기서열 상동성 비교법을 이용하여 종을 동정하였다. 이들 가운데 Cryptococcus podzolicus가 11균주를 포함하는 Cryptococcus 속 균이 전체 분리 균주 중 16균주(16%)로 가장 많이 분리되었고, 다음으로 Debaryomyces hansenii와 Trichorsporon asahii도 각각 6주씩 분리되었다.

• 한국균학회지
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• 제45권4호
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• pp.259-269
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• 2017

대전광역시 하천들의 효모 종 다양성을 조사하기 위하여 먼저 대전광역시 동남부와 시내를 흐르는 대전천과 서남부의 갑천에 있는 물과 주변 토양들을 2016년 8월과 2017년 2월에 각각 148점을 동일 장소에서 채취하여 야생효모들을 분리, 동정하였다. 여름 채취 물과 주변 토양 74점에서 23종 37균주의 야생효모들이 분리된 반면에 겨울 채취 시료들에서는 약 2배 이상 많은 34종 83균주가 분리되었다. 이들 3대 하천에서 가장 많이 분리된 야생효모는 Candida속 균으로 전체 42%이었고 Cryptococcus속 균과 식품에서 주로 분리되는 Saccharomyces속 균들이 각각 7%와 6%로 많이 분리되었다. 종 수준에서는 Candida tropicalis가 25균주로 가장 많았으며 여름 시료와 겨울 시료에서 공통으로 분리된 효모들은 Aureobasidium pullulans 등 13종이었다.

• 한국세라믹학회지
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• 제44권1호
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• pp.6-11
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• 2007

The rheological properties of slag cement pastes by effect of particle size distribution of binder were investigated using a Rheostress 1 rheometer (Haake) with a cylindrical spindle and the relationship between fluidity particle size distribution using the Rosin-Rammler equation. Samples are combined the two types of slag powder and OPC, fine slag particles sized Elaine specific surface area $8,000cm^2/g$, coarse slag particles sized Elaine specific surface area $2,000cm^2/g$, intermediate OPC particles $3,450cm^2/g$, used to search for the combination that would yield the best quality product. The all flow curves which were measured by rheometer showed hysterisis and could be classified into 4 types. When the combination was based on a ratio of 15-20 vol% fine particles, 40-50 vol% intermediate particles, 30-40 vol% coarse particles of the total volume, a high fluidity and low yield-strength was achieved. The Rosin-Rammler function can explain aboved correlation flow curve types. On type 1, the n-value had a correlation with plastic viscosity however the blend of type 2 and 3 showed consistent n-value regardless of plastic viscosity. In addition, the blend in type 4 tended to a rise in fluidity according to the increase of the n-value.

• KSBB Journal
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• 제14권6호
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• pp.702-706
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• 1999

대표적인 양식 해조류인 방사무늬 김 엽체를 대상으로 하여 산 처리에 의한 유전형질의 표현 변화를 differential display기법으로 비교하여 보았다. 방사무늬 김 엽체를 0.05% HCl을 첨가한 해수(pH 3.0)에서 5분간 처리한 후 각각 10분, 30분, 60분 그리고 4시간동안 멸균 해수에서 정치 배양시키면서, RNA를 추출하여 cDNA합성, PCR 증폭, agarose gel 전기영동 및 DNA 염기배열을 조사하였다. 그 결과 arbitrary primer OPA 1(CAGGCCCTTC)을 사용하여 differential display한 경우, 산 처리 후 30분간 멸균 해수에서 정치 배양한 엽체에서 특이적으로 RNA 합성이 일어나지 않은 유전자를 분리할 수 있었으며, 그 염기서열을 비교한바 이 유전자 fragment(605 bp)는 dethiobiotin synthetase 유전자와 93%의 높은 상동성을 가진 것으로 나타났다.

• BMB Reports
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• 제47권11호
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• pp.625-630
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• 2014

Defensins, which are small cationic molecules produced by organisms as part of their innate immune response, share a common structural scaffold that is stabilized by three disulfide bridges. Coprisin is a 43-amino acid defensin-like peptide from Copris tripartitus. Here, we report the intramolecular disulfide connectivity of cysteine-rich coprisin, and show that it is the same as in other insect defensins. The disulfide bond pairings of coprisin were determined by combining the enzymatic cleavage and mass analysis. We found that the loss of any single disulfide bond in coprisin eliminated all antibacterial, but not antifungal, activity. Circular dichroism (CD) analysis showed that two disulfide bonds, Cys20-Cys39 and Cys24-Cys41, stabilize coprisin's ${\alpha}$-helical region. Moreover, a BLAST search against UniProtKB database revealed that coprisin's ${\alpha}$-helical region is highly homologous to those of other insect defensins.

• Parasites, Hosts and Diseases
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• 제54권6호
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• pp.751-758
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• 2016

This study aimed at constructing a draft genome of the adult female worm Toxocara canis using next-generation sequencing (NGS) and de novo assembly, as well as to find new genes after annotation using functional genomics tools. Using an NGS machine, we produced DNA read data of T. canis. The de novo assembly of the read data was performed using SOAPdenovo. RNA read data were assembled using Trinity. Structural annotation, homology search, functional annotation, classification of protein domains, and KEGG pathway analysis were carried out. Besides them, recently developed tools such as MAKER, PASA, Evidence Modeler, and Blast2GO were used. The scaffold DNA was obtained, the N50 was 108,950 bp, and the overall length was 341,776,187 bp. The N50 of the transcriptome was 940 bp, and its length was 53,046,952 bp. The GC content of the entire genome was 39.3%. The total number of genes was 20,178, and the total number of protein sequences was 22,358. Of the 22,358 protein sequences, 4,992 were newly observed in T. canis. Following proteins previously unknown were found: E3 ubiquitin-protein ligase cbl-b and antigen T-cell receptor, zeta chain for T-cell and B-cell regulation; endoprotease bli-4 for cuticle metabolism; mucin 12Ea and polymorphic mucin variant C6/1/40r2.1 for mucin production; tropomodulin-family protein and ryanodine receptor calcium release channels for muscle movement. We were able to find new hypothetical polypeptides sequences unique to T. canis, and the findings of this study are capable of serving as a basis for extending our biological understanding of T. canis.

• 생명과학회지
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• 제17권8호통권88호
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• pp.1034-1038
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• 2007

하이퍼리신(Hypericin, HyH)은 예로부터 성 요한의 풀(St. John's Wort)로 널리 알려져 있는 서양고추나물(Hypericum perforatum)에서 추출되는 약리성분이다. 서양고추나물은 국내에서는 자생하지 않으나 같은 속의 고추나물(H. erectum) 등이 이속에 속하며 우리나라에 자생한다 . 고추나물을 조직배양으로 RNA를 추출하고 cDNA를 합성한 후 Hyp 유전자를 추출하여 서열화한 결과, 전체 크기는 732 bp로 나타났으며 서양고추나물의 HyH-1과 거의 99.8% 서열 일치를 나타내었다. 이 서열의 152개 아미노산 역시 서양고추나물의 항산화효소와 98% 일치하였으며 자작나무와 능금속 식물에서 유발되는 알레르기 유발유전자와 약 60% 일치를 나타내었다. 본 연구 결과 우울증치료제로 사용되는 하이퍼리신 추출에 우리나라 자생종인 고추나물이 이용될 수 있을 것으로 사료된다.