• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.20-27
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• 2016

Lactobacillus kefiranofaciens ZW3 was obtained from kefir grains, which have high lactose hydrolytic activity. In this study, a heterodimeric LacLM-type β-galactosidase gene (lacLM) from ZW3 was isolated, which was composed of two overlapping genes, lacL (1,884 bp) and lacM (960 bp) encoding large and small subunits with calculated molecular masses of 73,620 and 35,682 Da, respectively. LacLM, LacL, and LacM were expressed in Escherichia coli BL21(DE3) and these recombinant proteins were purified and characterized. The results showed that, compared with the recombinant holoenzyme, the recombinant large subunit exhibits obviously lower thermostability and hydrolytic activity. Moreover, the optimal temperature and pH of the holoenzyme and large subunit are 60℃ and 7.0, and 50℃ and 8.0, respectively. However, the recombinant small subunit alone has no activity. Interestingly, the activity and thermostability of the large subunit were greatly improved after mixing it with the recombinant small subunit. Therefore, the results suggest that the small subunit might play an important role in maintaining the stability of the structure of the catalytic center located in the large subunit.

• Animal Systematics, Evolution and Diversity
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• v.31 no.3
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• pp.182-190
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• 2015

Two heterotrichid ciliates, Climacostomum virens (Ehrenberg, 1838) Stein, 1859 from brackish water and freshwater, and Fabrea salina Henneguy, 1890 from a solar saltern, were collected in Korea. They are novelly investigated in Korea by means of live observation, protargol staining and nuclear small subunit (SSU) rRNA gene sequencing. Climacostomum virens is characterized by pouch-like body shape, body length of $200-370{\mu}m$ in vivo, conspicuous cytopharyngeal tube, macronuclei ribbon-like shape, and one to four in number, with or without symbiont algae in cytoplasm, 34-66 somatic kineties, 67-113 adoral zone of membranelles, 8-42 peristomial kineties, 24-37 apical membranelles. SSU rDNA sequence size is 1,591 bp and GC contents 48.52%. Fabrea salina is also characterized by scoop-like body shape with proboscis, body length of $190-240{\mu}m$ in vivo, one to two rod-shaped macronuclei, oval micronuclei, grayish green cortical granules, 104-186 somatic kineties, 4-8 preoral kineties, 7-19 peristomial kineties and fragmented paroral membrane. SSU rDNA sequence size is 1,598 bp and GC contents 47.50%.

• Parasites, Hosts and Diseases
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• v.44 no.3
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• pp.251-254
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• 2006

Monoclonal antibody (mAb) Tg786 against Toxoplasma gondii has been found to detect a 42-kDa rhoptry protein (ROP6) which showed protease activity and host cell binding characteristics after secretion. Using the mAb, a colony containing a 3'-UTR was probed in a T. gondii cDNA expression library. A full length cDNA sequence of the rhoptry protein was completed after 5'-RACE, which consisted of 1,908 bp with a 1,443 bp ORF. The deduced amino acid sequence of ROP6 consisted of a polypeptide of 480 amino acids without significant homology to any other known proteins. This sequence contains an amino terminal stop transfer sequence downstream of a short neutral sequence, hydrophilic middle sequence, and hydrophobic carboxy terminus. It is suggested that the ROP6 is inserted into the rhoptry membrane with both N- and C-termini.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.3
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• pp.302-310
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• 2017

Interferon regulatory factor 8 (IRF8) is essential for the development of B and T cells, as well as for the activity of dendritic cells and macrophages. We performed molecular characterization of IRF8 from rock fish, Sebastes schlegelii (Ss), and investigated the spatial and temporal profile of mRNA expression after challenge with lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (poly I:C), or Streptococcus iniae. The full-length cDNA sequence of SsIRF8 was 1,657 bp, containing an ORF of 1,266 bp. The gene had a predicted molecular mass of 47.7 kDa and an isoelectric point of 5.99. The amino acid sequence coded by this gene showed the highest degree of identity (90.8%) and similarity (96.2%) with IRF8 from Oplegnathus fasciatus. The SsIRF8 mRNA was expressed ubiquitously, at varying levels, with the highest level of expression observed in the spleen. To confirm the role of SsIRF8 in mediating the immune response, we measured SsIRF8 mRNA expression in the splenic tissue at different time points after injection with LPS, poly I:C, or S. iniae. The qRT-PCR results showed that SsIRF8 mRNA expression in the poly I:C-injected group was highly upregulated 6 hr after exposure (P<0.05). Expression of SsIRF8 mRNA in the S. iniae-injected group peaked at 24 hr. These results suggest that SsIRF8 might be important in regulating the strength of the rockfish immune response to immunostimulatory agents.

• Biomedical Science Letters
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• v.13 no.1
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• pp.33-38
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• 2007

The aim of this work was to validate a rapid and an accurate method for detecting Mycobacterium leprae in clinical specimens using nested PCR targeting M. leprae-specific repetitive element (RLEP) sequence. The primers were derived from the RLEP sequence which yield a 272 bp outer product and a 230 bp inner product. The specificity and the sensitivity of the nested PCR were compared with those of single PCR for detecting M. leprae using DNAs isolated from reference strain and various species of Mycobacterium. The results showed that the sensitivity of the nested PCR was about 100 to 1,000 times higher than that of the single PCR and also showed that both the single and the nested PCR were highly specific to M. leprae. Subsequently, the usefulness of the single and nested PCR was evaluated with clinical samples isolated from leprosy patients. The number of positive detections by the single and the nested PCR with a total of 20 specimens from leprosy patients were 9 (45%) and 20 (100%), respectively. The results clearly showed that nested PCR has highest sensitivity in detecting M. leprae from clinical specimens. Therefore, nested primers targeting RLEP sequence developed in this study seems to be useful to detect the presence of M. leprae.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.84-84
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• 2003

DNA methylation is involved in epigenetic processes such as X-chromosome inactivation, imprinting and silencing of transposons. DNA methylation is a highly plastic and critical component of mammalian development The DNA methyltransferases (Dnmts) are responsible for the generation of genomic methylation patterns, which lead to transcriptional silencing. The maintenance DNA methyltransferase enzyme, Dnmt 1, and the de novo methyltransferase, Dnmt3a and Dnmt3b, are indispensable for development because mice homozygous for the targeted disruption of any of these genes are not viable. The occurrence of DNA methylation is not random, and it can result in gene silencing The mechanisms underlying these processes are poorly understood. It is well established that DNA methylation and histone deacetylation operate along a common mechanistic pathway to repress transcription through the action of methyl-binding domain proteins (MBDs), which are components of, or recruit, histone deacetylase (HDAC) complexes to methylated DNA. As a basis for future studies on the role of the DNA-methyl-transferase in porcine development, we have isolated and characterized a partial cDNA coding for the porcine Dnmt1. Total RNA of testis, lung and ovary was isolated with TRlzol according to the manufacture's specifications. 5 ug of total RNA was reverse transcribed with Super Script II in the presence of porcine Dnmt 1 specific primers. Standard PCRs were performed in a total volume of 50 ul with cDNA as template. Two DNA fragmenets in different position were produced about 700bp, 1500bp and were cloned into pCR II-TOPO according to the manufacture's specification. Assembly of all sequences resulted in a cDNA from 158bp of 5'to 4861bp of 3'compare with the known human maintenance methyltransferase. Now, we are cloning the unknown Dnmt 1 region by 5'-RACE method and expression of Dnmt 1 in tissues from adult porcine animals.

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.234-239
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• 1992

The experiment was performed to find out the possibilities to detect virus infection in oyster mushrooms, Pleurotus species by analysis of doublestranded ribonucleic acid (ds RNA). Ds RNA segments were extracted from virus infected isolates which grew abnormally. But virus free isolates didn't show any ds RNA segments. The ds RNA was consisted of one large segment of 8100 base pairs (bp) and 4 smaller segments with 2170, 2120, 1980 and 1984 bp. Whereas, cell free virus particles showed only one larger ds RNA segment. The ds RNA was dissolved by RNase A in low salt, 0.1 M SSC and melted at $85^{\circ}C$. It was possible to use the ds RNA analysis for detecting virus infection directly from the host cells.

• Journal of Marine Bioscience and Biotechnology
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• v.8 no.1
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• pp.18-23
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• 2016

It is important to design photobioreactor by cheap material for economical microalgal biomass production. In this study, two types of marine photobioreactors (MPBR), made by either polyvinyl chloride (MPBR-PVC) or high density poly ethylene (MPBR-HDPE), are used and performance of these were compared. Tetraselmis sp. KCTC 12236BP is a green marine alga that isolated from Ganghwa Island, Korea, and the strain was used for marine cultivations using MPBR-PVC and MPBR-HDPE. The cultivations were performed three times in the spring season of 2012 using MPBR-PVC and of 2013 using MPBR-HDPE in the coastal area of Young Heung Island. As the results, MPBR-PVC shows higher biomass productivities than MPBR-HDPE, due to its high light transmittance. In the cultivations using MPBR-PVC, the average sea water temperature was $11.5^{\circ}C$ during the first experiment and $16.5^{\circ}C$ during the second and third experiments. Average light intensities during three times for experiments were 407.5, 268.1 and $273.0{\mu}{\cdot}E{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The maximum fresh cell weight and average biomass productivity were $1.2g{\cdot}L^{-1}$ and $0.12g{\cdot}L^{-1}{\cdot}day^{-1}$. These results showed that Tetraselmis sp. KCTC12236BP were adapted well with the environmental conditions from ocean, and grow in the MPBR-PVC and MPBR-HDPE.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.276-282
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• 2004

Marginal Zn deficiency is prevalent through the world and yet human zinc status has not been properly assessed due to the lack of a reliable diagnostic indicator. One potential possibility for zinc status assessment using Zn-binding protein, metallothionein (MT)-mRNA, has been proposed. The purpose of the present study was aimed to show whether measurement of mononuclear cell (MNC) MT mRNA, using a competitive-reverse transcriptase-polymerase chain reaction (competitive-RT-PCR) assay, could indicate zinc status in human subjects. In this study, MNC MT-mRNA expression was measured using a competitive-RT-PCR to compare before and after 14 days of zinc supplementation (50 mg Zn/das zinc gluconate). RT-PCR oligonucleotide primers which were designed to amplify both a 278 bp segment of the human MT-2A cDNA and a 198 bp mutant competitor cDNA template from MNCs, were prepared. MT-2A mRNA was normalized by reference to the housekeeping gene, $\beta$-actin, mRNA for which was also measured by competitive-RT-PCR. There was considerable inter-individual variation in MT-mRNA concentration and yet, the mean MT-2A mRNA level increased 4.7-fold after Zn supplementation, as compared to before Zn supplementation. This MT-2A mRNA level was shown as the same pattern and, even more sensitive assay, compared to the conventional plasma and red blood cells (RBCs) Zn assessment in which plasma and RBCs zinc levels increased 2.3- and 1.2-fold, respectively (p<0.05). We suggest that MT competitive-RT-PCR can be a useful assessment tool for evaluating human zinc status.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.238-244
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• 2003

During the life cycle, plants have to suffer from various environmental stresses. A common element in response to many environmental stresses is cellular dehydration. Dehydrins are a family of proteins commonly induced by environmental stresses associated with low temperature or dehydration and during seed maturation drying. For the study in the defense mechanism against various stresses, a cDNA clone encoding a dehydrin gene was isolated from a cDNA library prepared from tab root mRNAs of Codonopsis lanceolata. The cDNA, designated ClDhn1, is 893 nucleotides long and has an open reading frame of 480 bp with a deduced amino acid sequence of 159 residues. The ClDhn1 amino acid sequence is highly hydrophilic and possesses two conserved repeats of characterized lysine­rich K­segment (KIKEKLPG), and a 7­serine residue stretch prior to the first lysine­rich repeat that is common to many dehydrins. The DEYGNP conserved motif is, however, modified in the sequence of ClDhn1 gene. The deduced amino acid sequence of ClDhn1 was compared with other plant dehydrinls and showed high homology with Solanum commersonii