• Biomedical Science Letters
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• v.18 no.3
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• pp.310-312
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• 2012

Cytochrome $b_5$ is involved in the reduction of methemoglobin back to hemoglobin, thereby maintaining normal function of the blood to carry oxygen around. Congenital abnormal condition of this enzyme causes a rare disease called methemoglobinemia. At least 4 different retropseudogenes are reported so far for cytochrome $b_5$. However, type III pseudogene has attracted most attention because it contains open reading frame in its structure. Although there is no evidence yet if this pseudogene is actually expressed in the cell or the blood the possibility of its expression needs to be elucidated. We have isolated type III pseudogene by polymerase chain reaction and cloned into pGEX-4T-1 expression vector followed by SDS-PAGE. Protein was expressed and the size of the expressed protein was 28 kDa as expected in its genetic code. This result also shows that the protein is not harmful for the viability of the microorganism. This study may contribute to the genetic diagnosis of cardiac diseases, possibly caused by cytochrome $b_5$.

• Journal of Microbiology and Biotechnology
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• v.22 no.8
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• pp.1059-1065
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• 2012

Biocatalytic transfer of oxygen in isolated cytochrome P450 or whole microbial cells is an elegant and efficient way to achieve selective hydroxylation. Cytochrome P450 CYP105P2 was isolated from Streptomyces peucetius that showed a high degree of amino acid identity with hydroxylases. Previously performed homology modeling, and subsequent docking of the model with flavone, displayed a reasonable docked structure. Therefore, in this study, in a pursuit to hydroxylate the flavone ring, CYP105P2 was co-expressed in a two-vector system with putidaredoxin reductase (camA) and putidaredoxin (camB) from Pseudomonas putida for efficient electron transport. HPLC analysis of the isolated product, together with LC-MS analysis, showed a monohydroxylated flavone, which was further established by subsequent ESI/MS-MS. A successful 10.35% yield was achieved with the whole-cell bioconversion reaction in Escherichia coli. We verified that CYP105P2 is a potential bacterial hydroxylase.

• BMB Reports
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• v.40 no.6
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• pp.875-880
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• 2007

Glucose oxidase (GOD) is an oxidoreductase catalyzing the reaction of glucose and oxygen to peroxide and gluconolacton (EC 1.1.3.4.). GOD is a widely used enzyme in biotechnology. Therefore the production of monoclonal antibodies and antibody fragments to GOD are of interest in bioanalytics and even tumor therapy. We describe here the generation of a panel of monoclonal antibodies to native and heat inactivated GOD. One of the hybridomas, E13BC8, was used for cloning of a single chain antibody(scFv). This scFv was expressed in Escherichia coli XL1-blue with the help of the vector system pOPE101. The scFv was isolated from the periplasmic fraction and detected by western blotting. It reacts specifically with soluble active GOD but does not recognize denatured GOD adsorbed to the solid phase. The same binding properties were also found for the monoclonal antibody E13BC8.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.23 no.1
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• pp.1-11
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• 1995

Thermospheric neutral winds and temperatures have been collected from the ground-based Fabry-Perot interferometer (FPI) at Thule Air Base ($76.5^{\circ}N{\;}69.0^{\circ}W$), Greenland since 1985. The thermospheric observations are obtained by determining the Doppler characteristics f the [OI] 6300 ${\AA}$ emissions of atomic oxygen. The FPI operates routinely during the winter season, with a limitation in the observation by the existence of clouds. For this study, data acquired from 1985 to 1991 were analyzed. The neutral wind measurements from these long-term measurements are used to investigate the influence of solar cycle variation on the high-latitude thermospheric dynamics. These data provide experimental results of the geomagnetic polar cap are also compared with the predictions of two semiempirical models : the vector spherical harmonics (VSH) model of Killeen et al. (1987) and the horizontal wind model (HWM) of Hedin et al. (1991). The experimental results show a good positive correlation between solar activity and thermospheric wind speed over the geomagnetic polar cap. The calculated correlation coefficient indicates that an increase of 100 in F10.7 index corresponds to an increase in wind speed of about 100 m/s. The model predictions reveal similar trends of wind speed variation as a function of solar activity, with the VSH and HWM models tending to overestimate and underestimate the wind speed, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.1
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• pp.21-26
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• 2001

To develop transgenic orchardgrass resistant to reactive oxygen species produced from environmental stresses, a vector with the cytosolic glutathione reductase cDNA (BcGRl) from Chinese cabbage was constructed under the control of the cauliflower mosaic virus 35S promoter and was introduced into orchardgrass using Agrobacterium tumefaciens EHA101. Transgenic plants from hygromycin-selected calli of orchardgrass did not show any morphological difference from wild-type plants. The results of PCR amplification and genomic Southern blot analysis confirmed the integration of foreign gene into the chromosome of transgenic orchardgrass. Northern blot analysis with total RNA from leaves also confirmed the constitutive expression of BcGR1 in transgenic orchardgrass.

• Journal of the Mineralogical Society of Korea
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• v.15 no.1
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• pp.44-58
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• 2002

A new polymorph of tridymite, an incommensurately modulated phase (IC phase), has been identified. While the symmetry of the IC lattice is same as that of the Ll phase, the geometry of the IC lattice structure is same as the basis of the L3 structure with a different modulation (modulation vector q=0.22 $c*_{H}$;$\lambda$ 37 ). On the other hand, the characteristic curved diffuse diffration observed from the Ll atoms could occur even at room phase suggests that the dynamic disordering of atoms, especially oxygen atoms could occur even at room temperature. The phase transition of Ll to L3 by grinding is gradual but very conspicuous: LllongrightarrowL1+IClongrightarrowIC+L3longrightarrowL3. However, it is revealed that real transition processes of individual grains are directly related to the local stress fields and preexisting microstructures.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.818-823
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• 2012

Tall fescue (Festuca arundinacea Schreb.) is an important cool season forage plant that is not well suited to extreme heat, salts, or heavy metals. To develop transgenic tall fescue plants with enhanced tolerance to abiotic stress, we introduced an alfalfa Hsp23 gene expression vector construct through Agrobacterium-mediated transformation. Integration and expression of the transgene were confirmed by polymerase chain reaction, northern blot, and western blot analyses. Under normal growth conditions, there was no significant difference in the growth of the transgenic plants and the non-transgenic controls. However, when exposed to various stresses such as salt or arsenic, transgenic plants showed a significantly lower accumulation of hydrogen peroxide and thiobarbituric acid reactive substances than control plants. The reduced accumulation of thiobarbituric acid reactive substances indicates that the transgenic plants possessed a more efficient reactive oxygen species-scavenging system. We speculate that the high levels of MsHsp23 proteins in the transgenic plants protect leaves from oxidative damage through chaperon and antioxidant activities. These results suggest that MsHsp23 confers abiotic stress tolerance in transgenic tall fescue and may be useful in developing stress tolerance in other crops.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.483-488
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• 2014

In order to improve the expression of heat-resistant xylanase XYNB from Aspergillus niger SCTCC 400264, XynB has been cloned into Pichia pastoris secretary vector pPIC9K. The XynB production of recombinant P. pastoris was four times that of E. coli, and the $V_{max}$ and specific activity of XynB reached $2,547.7{\mu}mol/mg$ and 4,757 U/mg, respectively. XynB still had 74% residual enzyme activity after 30 min of heat treatment at $80^{\circ}C$. From the van der Waals force analysis of XYNB (ACN89393 and AAS67299), there is one more oxygen radical in AAS67299 in their catalytic site, indicating that the local cavity is much more free, and it is more optimal for substrate binding, affinity reaction, and proton transfer, etc, and eventually increasing enzyme activity. The H-bonds analysis of XYNB indicated that there are two more H-bonds in the 33rd Ser of XYNB (AAS67299) than in the 33rd Ala(ACN89393 ), and two H-bonds between Ser70 and Asp67.

• Korean Journal of Remote Sensing
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• v.32 no.3
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• pp.221-234
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• 2016

In Korea, most industrial parks and major cities are located in coastal areas, which results in serious environmental problems in both coastal land and ocean. In order to effectively manage such problems especially in coastal ocean, water quality should be monitored. As there are many factors that influence water quality, the Korean Government proposed an integrated Water Quality Index (WQI) based on in situmeasurements of ocean parameters(bottom dissolved oxygen, chlorophyll-a concentration, secchi disk depth, dissolved inorganic nitrogen, and dissolved inorganic phosphorus) by ocean division identified based on their ecological characteristics. Field-measured WQI, however, does not provide spatial continuity over vast areas. Satellite remote sensing can be an alternative for identifying WQI for surface water. In this study, two schemes were examined to estimate coastal WQI around Korea peninsula using in situ measurements data and Geostationary Ocean Color Imager (GOCI) satellite imagery from 2011 to 2013 based on machine learning approaches. Scheme 1 calculates WQI using estimated water quality-related factors using GOCI reflectance data, and scheme 2 estimates WQI using GOCI band reflectance data and basic products(chlorophyll-a, suspended sediment, colored dissolved organic matter). Three machine learning approaches including Random Forest (RF), Support Vector Regression (SVR), and a modified regression tree(Cubist) were used. Results show that estimation of secchi disk depth produced the highest accuracy among the ocean parameters, and RF performed best regardless of water quality-related factors. However, the accuracy of WQI from scheme 1 was lower than that from scheme 2 due to the estimation errors inherent from water quality-related factors and the uncertainty of bottom dissolved oxygen. In overall, scheme 2 appears more appropriate for estimating WQI for surface water in coastal areas and chlorophyll-a concentration was identified the most contributing factor to the estimation of WQI.

• Molecules and Cells
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• v.19 no.2
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• pp.191-197
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• 2005

The human immunodeficiency virus type 1 (HIV-1) Tat protein transduction domain (PTD) is responsible for highly efficient protein transduction across plasma membranes. In a previous study, we showed that Tat-Cu,Zn-superoxide dismutase (Tat-SOD) can be directly transduced into mammalian cells across the lipid membrane barrier. In this study, we fused the human SOD gene with a Tat PTD transduction vector at its N- and/or C-terminus. The fusion proteins (Tat-SOD, SOD-Tat, Tat-SOD-Tat) were purified from Escherichia coli and their ability to enter cells in vitro and in vivo compared by Western blotting and immunohistochemistry. The transduction efficiencies and biological activities of the SOD fusion protein with the Tat PTD at either terminus were equivalent and lower than the fusion protein with the Tat PTD at both termini. The availability of a more efficient SOD fusion protein provides a powerful vehicle for therapy in human diseases related to this anti-oxidant enzyme and to reactive oxygen species.