• Journal of Microbiology and Biotechnology
• /
• v.28 no.9
• /
• pp.1482-1492
• /
• 2018

Fusarium oxysporum trypsin (FOT) is a fungal serine protease similar to mammal trypsin. The FOT could be successfully expressed in Pichiapastoris by engineering the natural propeptide APQEIPN. In this study, we constructed two recombinant enzymes with engineered amino acid sequences added to the N-terminus of FOT and expressed in P. pastoris. The N-terminal residues had various effects on the structural and functional properties of trypsin. The FOT, and the recombinants TE (with peptide YVEF) and TS (with peptide YV) displayed the same optimum temperature ($40^{\circ}C$) and pH (8.0). However, the combinants TE and TS showed significantly increased thermal stability at $40^{\circ}C$ and $50^{\circ}C$. Moreover, the combinants TE and TS also showed enhanced tolerance of alkaline pH conditions. Compared with those of wild-type FOT, the intramolecular hydrogen bonds and the cation ${\pi}$-interactions of the recombinants TE and TS were significantly increased. The recombinants TE and TS also had significantly increased catalytic efficiencies (referring to the specificity constant, $k_{cat}/K_m$), 1.75-fold and 1.23-fold than wild-type FOT. In silico modeling analysis uncovered that the introduction of the peptides YVEF and YV resulted in shorter distances between the substrate binding pocket (D174, G198, and G208) and catalytic triad (His42, Asp102, and Ser180), which would improve the electron transfer rate and catalytic efficiency. In addition, N-terminal residues modification described here may be a useful approach for improving the catalytic efficiencies and characteristics of other target enzymes.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.1
• /
• pp.53-58
• /
• 2002

To better understand the reservoir host range and distribution of hantaviruses in small mammal populations in Korea, a serological survey was conducted on 1,375 wild rodents and 62 insectivores captured in seven provinces during the six-year period, 1995 to 2000. As determined by the indirect immunofluorescent antibody (IFA) test, 90 ($13.1\%$) of 685 Apodemus agrarius, 47 ($13.6\%$) of 345 Apodemus peninsulae, and 4 ($6.5\%$) of 62 Crocidura laciura were seropositive against the Hantaan virus, while 38 ($13.5\%$) of 282 Eothenomys regulus were seropositive against the Puumala virus. Serological evidence for hantavirus infection was not found in 50 Microtus fortis, six Micromys minutus, six Mus musculus, and one Cricetulus triton. Our serological data indicate that hemorrhagic fever with renal syndrome (HFRS)-related hantaviruses are widely distributed in indigenous rodents in Korea. Particularly noteworthy was the high seropositivity rates among Apodemus peninsulae and Eothenomys regulus captured in certain mountainous regions, suggesting that HFRS may be under-reported among nearby residents or among individuals who might visit such areas for recreational or occupational purposes.

• Journal of the Korean Society of Radiology
• /
• v.14 no.3
• /
• pp.253-259
• /
• 2020

Mammography has the advantage of being economical, simple and effective in detecting microcalcification, but breast is a highly sensitive organ and is accompanied by the risk of an over-exposure. While accurate dose assessments are important to prevent this, current breast dose assessments are limited to breast implant patients. This purpose of this study was to identify dose variations due to tube voltages by forming a mock-up with breast implants for an accurate dosimetric assessment on breast implant patients. As a result, doses from the presence of breast implants were smaller than those from the absence of the mammal. As the result of the change of the voltage to 26, 28, 30, and 32 kV, the imcreased tube voltage included larger dose regardless of the presence of Breast implant. Therefore, it is believed that diagnosis recommendations for breast implants will be possible if further studies on internal and external bioretical imaging and quality assessment are carried out as the basis for this study.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.21 no.5
• /
• pp.29-37
• /
• 2018

Biodiversity refers to the diversity of organisms originating from all sources, including terrestrial ecosystems, aquatic ecosystems, and complex ecosystems and it is considered to be the standard of the area to be preserved and protected. So The Importance of environmental assessment for biodiversity conservation is increasing and International efforts to quantify biodiversity and to develop indices have been made, but there are insufficient researches on the use of biomass databases and their quantification in Korea. In this study, the biodiversity map was constructed using the 3rd National Ecosystem Survey Mammal Data with three spatial units(Administrative Area, 1:5,000 index map, hexagonal lattice). and the difference of map constructed by spatial unit was suggested to help research on quantification and evaluation of biodiversity in the future. As a result of the study, biodiversity index for the same area varied according to the spatial unit and overall average and standard deviation were different too. Therefore it is necessary to utilize appropriate spatial unit considering the suitability and purpose of quantification rather than using specific unit. It also showed the necessity of establishing a standard for biodiversity index as a result of comparative analysis with ecosystem and nature map. Based on this research, comprehensive efforts should be made for the sustainable development of the country through further research and institutional improvement for quantification and evaluation of biodiversity, set standards.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.4 no.2
• /
• pp.155-162
• /
• 2002

Cytochrome P45O (CYP) gene has been known to play one of the most important roles in metabolizing the exogenous materials. In insect, CYP is particularly known to detoxify toxic materials by adding oxygen molecule to the hydrophobic region of the materials. Thus, CYP-dependent metabolism is associated with the adaptation of insect to host plant chemicals. This in turn is known to be one of the driving forces for CYP diversification. In the present study, we cloned seven gene fragments of CYP 4 (CYP4) family from the midgut of the beet armyworm, Spodoptera exigua, through RT.PCT, Sequence analysis of the product showed the gene fragment to contain an open reading frame of ~150 amino acids, consisted of ~450 bp. The cloned gene fragments contained typical, conserved regions found in CYP4 family. Pairwise comparison of the deduced amino acid sequences among seven clones ranged in divergence from 0% to 52.86% and resulted in five distinct clones. The other two clones were identical or differ by one amino acid respectively to the corresponding clone, although each differed by ten nucleotides. Analysis of correlation between GenBank-registered, full length CYP4 and the cloned fragments resulted in statistically significant relationship ($r^{2}$ = 0.96085; p < 0.001), suggesting utility of the partial sequences as such full-length sequences. Phylogenetic analysis of the clones with GenBank-registered insect and mammal CYP4 family sequences by parsimony and several distance methods subdivided the clones into two groups: tones belonging to CYP4S and the others to CYP4M families.

• Journal of Forest and Environmental Science
• /
• v.31 no.4
• /
• pp.261-266
• /
• 2015

We investigated habitat characteristics of the yellow-throated marten Martes flavigula (Carnivora : Mustelidae) using geographic information system (GIS). GPS coordinates of the target mammal traces and seven habitat factors were used for the GIS analysis. The Odaesan National Park (ONP) is selected as a study area for GIS analysis of the habitat characteristics. According to the GIS analysis of whole area of ONP, main forest type was broadleaf trees which occupy 72% of forests. Trees of 4th to 6th age-calss account for 93% of the ONP forests. The mean elevation and slope of ONP was 901 m and $22.1^{\circ}$, respectively. According to the GIS analysis of M. flavigula habitats in ONP, most M. flavigula traces were found in borad-leaf forests and coniferous forests which are main forest types of ONP. In addition, the yellow-throated marten recorded a relatively high appearance rate of 7% in unstocked forests, which account for much less than 1% of the area of ONP. Most of the marten traces were found in forests with trees of 4th to 6th age-classes. The traces were found in the forest types in higher elevation (1,080.3 m) and lower slope ($15.0^{\circ}$) on average, compared with those of ONP. Appearance rate of the marten traces was 96% in range less than 600 m from the water. The traces were frequently found in areas far distantly beyond 1,400 m range from human residental areas and cultivated areas.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.10
• /
• pp.5925-5928
• /
• 2013

Objective: This study aimed to examine the relationship between expression of mammal target of rapamycin (mTOR) and phosphorylation of mTOR (p-mTOR) protein in the PI3K/Akt/mTOR signaling pathways in gastrointestinal stromal tumors and relatiuonships with clinical factors. Methods: Immunohistochemistry was used to detect the expression of the associated proteins mTOR, p-mTOR, and phosphorylation of the tumor suppressor genes PTEN, P27, VEGF, and EGFR in 40 cases of gastrointestinal stromal tumors, with division into a very low and low risk group as well as a moderate and high risk group. Results: The positive rate of mTOR and p-mTOR was significantly increased in the moderate and high risk group compared with the very low and low risk group. The difference was statistically significant (P<0.05). When grouped according to size, the positive mTOR expression rate exhibited a statistical difference (P<0.05), which was significantly increased in the group of tumors larger than 5 cm. The difference in the positive mTOR and p-mTOR expression rate exhibit no statistical significance among the PTEN, P27, VEGF, and EGFR expression subgroups (P>0.05). Conclusion: The different expressions of mTOR and p-mTOR in the signal transduction pathway of gastrointestinal stromal tumor in the different degree-of-risk groups suggested that the mTOR and p-mTOR of the signal transduction pathway serve an important function in the occurrence and development of gastrointestinal stromal tumors.

• BMB Reports
• /
• v.41 no.6
• /
• pp.415-434
• /
• 2008

Phosphoinositide-specific phospholipase C is an effector molecule in the signal transduction process. It generates two second messengers, inositol-1,4,5-trisphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. Currently, thirteen mammal PLC isozymes have been identified, and they are divided into six groups: PLC-$\beta$, -$\gamma$, -$\delta$, -$\varepsilon$, -$\zeta$ and -$\eta$. Sequence analysis studies demonstrated that each isozyme has more than one alternative splicing variant. PLC isozymes contain the X and Y domains that are responsible for catalytic activity. Several other domains including the PH domain, the C2 domain and EF hand motifs are involved in various biological functions of PLC isozymes as signaling proteins. The distribution of PLC isozymes is tissue and organ specific. Recent studies on isolated cells and knockout mice depleted of PLC isozymes have revealed their distinct phenotypes. Given the specificity in distribution and cellular localization, it is clear that each PLC isozyme bears a unique function in the modulation of physiological responses. In this review, we discuss the structural organization, enzymatic properties and molecular diversity of PLC splicing variants and study functional and physiological roles of each isozyme.

• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.2
• /
• pp.155-161
• /
• 2009

Mammal microsomal glutathione transferase 1 (MGST1) can conjugate many toxic or carcinogenic substances and depress oxidative stress. In this study, Chicken MGST1 and its variants were cloned for the first time and were composed of 956 or 944 nucleotides. The 12 nt deletion in the exon 2 did not alter the GT-AG rule and the ORFs for the two MGST1 variants were the same, which both comprised 465 nucletides and encoded a peptide with 155 amino acids. It was found that the two different splice variants identified using RT-PCR expressed in all three organs investigated of Dwarf Brown Chicken, namely liver, spleen and shell gland. Moreover, the expression level of MGST1 mRNA in the liver of Dwarf Brown chickens was the highest (p<0.01), and there were no significant differences between the spleen and the shell gland. These results provide a base for studying the biological function of Chicken MGST1.

• Journal of Environmental Impact Assessment
• /
• v.21 no.4
• /
• pp.593-607
• /
• 2012

The Ministry of Environment have started the 'National Ecosystem Survey' since 1986. It has been carried out nationwide every ten years as the largest survey project in Korea. The second one and the third one produced the GIS-based inventory of species. Three survey methods were different from each other. There were few studies for species distribution using national survey data in Korea. The purposes of this study are to test species distribution models for finding the most suitable modeling methods for the National Ecosystem Survey data and to investigate the modeling results according to survey methods and taxonominal group. Occurrence data of nine species were extracted from the National Ecosystem Survey by taxonomical group (plant, mammal, and bird). Plants are Korean winter hazel (Corylopsis coreana), Iris odaesanensis (Iris odaesanensis), and Berchemia (Berchemia berchemiaefolia). Mammals are Korean Goral (Nemorhaedus goral), Marten (Martes flavigula koreana), and Leopard cat (Felis bengalensis). Birds are Black Woodpecker (Dryocopus martius), Eagle Owl (Bubo Bubo), and Common Buzzard (Buteo buteo). Environmental variables consisted of climate, topography, soil and vegetation structure. Two modeling methods (GAM, Maxent) were tested across nine species, and predictive species maps of target species were produced. The results of this study were as follows. Firstly, Maxent showed similar 5 cross-validated AUC with GAM. Maxent is more useful model to develop than GAM because National Ecosystem Survey data has presence-only data. Therefore, Maxent is more useful species distribution model for National Ecosystem Survey data. Secondly, the modeling results between the second and third survey methods showed sometimes different because of each different surveying methods. Therefore, we need to combine two data for producing a reasonable result. Lastly, modeling result showed different predicted distribution pattern by taxonominal group. These results should be considered if we want to develop a species distribution model using the National Ecosystem Survey and apply it to a nationwide biodiversity research.