• The Journal of Engineering Geology
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• v.18 no.4
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• pp.577-586
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• 2008

The formation of acid mine drainage is closely related to water chemistry and ochreous sprecipitates formed at the bottom of creeks because it is initially derived from the possible water-rock interaction in abandoned waste metals at the mine. According to analyses on water, precipitates, and alteration characters of ore metals in Dalseone mine, whitish precipitates formed at pHs above 5 while schwertmannite formed at pH $3{\sim}4$. Water chemistry vary with seasons. The water chemistry of the treatment site measured ir Octoter 2002 is characterized by lower pH, and higher Al, Zn, Cu contents relative to those in March, 2003. In the latter case, As and Cl contents are very high. $^{27}Al$ MAS NMR data show the presence of predominant octahedral Al in whitish precipitates. Metal ore minerals dissolve at margins, cleavage, or comer of crystals where reactive sites are potential. Pyrite dissolves, forming etch pits or smooth faces on the edge.

• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.337-345
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• 2014

Pichia pastoris is one of the most widely used expression systems for the secretory expression of recombinant proteins. The secretory expression in P. pastoris usually makes use of the prepro $MAT{\alpha}$ sequence from Saccharomyces cerevisiae, which has a dibasic amino acid cleavage site at the end of the signal sequence. This is efficiently processed by Kex2 protease, resulting in the secretion of high levels of proteins to the medium. However, the proteins that are having the internal accessible dibasic amino acids such as KR and RR in the coding region cannot be expressed using this signal sequence, as the protein will be fragmented. We have identified a new signal sequence of 18 amino acids from a P. pastoris protein that can secrete proteins to the medium efficiently. The PMT1-gene-inactivated P. pastoris strain secretes a ~30 kDa protein into the extracellular medium. We have identified this protein by determining its N-terminal amino acid sequence. The protein secreted has four DDDK concatameric internal repeats. This protein was not secreted in the wild-type P. pastoris under normal culture conditions. We show that the 18-amino-acid signal peptide at the N-terminal of this protein is useful for secretion of heterologous proteins in Pichia.

• Applied Biological Chemistry
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• v.38 no.6
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• pp.522-527
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• 1995

To develop an antiviral agent for the rice black-streaked dwarf virus (RBSDV), a hammerhead type ribozyme, which has a potential target site on the genome segment 3, was designed. Oligonucleotides for the ribozyme and its substrate were synthesized, annealed, and cloned into a plasmid pBluescript II KS(+). Ribozyme and substrate RNAs were then synthesized by in vitro transcription with $T_3$ RNA polymerase, obtaining RNAs in expected size, 193 and 182 nucleotides, respectively. The substrate RNA was efficiently cleaved into two fragments when incubated with the ribozyme at $55^{\circ}C$, while the cleavage was not detected at $37^{\circ}C$. In addition, the segment 3 RNA of RBSDV was also cleaved into two fragments by the same ribozyme at $55^{\circ}C$. Taken together, our results demonstrated that the hammerhead ribozyme has an in vitro endonucleolytic activity and may be used as an antiviral agent in transgenic plants.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.217-223
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• 2004

A cathepsin L-like cysteine protease, v-cath, encoded by the baculovirus has been shown to playa role in host liquefaction. We have identified a v-cath gene in the silkworm virus, Bombyx mori nuclear polyhedrosis virus (BmNPV) K1 strain. The 969 bp v-cath has an open reading frame of 323 amino acids. A putative cleavage site and catalytic sites were conserved in BmNPV-K1 v-cath. The predicted three-dimensional structure of BmNPV-K1 v-cath revealed that the overall fold of BmNPV-K1 v-cath is similar to that of other proteases of the papain family. The deduced amino acid sequence of BmNPV-K1 v-cath showed 98% and 97% protein sequence identity to BmNPV T3 strain and to Autographa californica nuclear polyhedrosis virus, respectively. The BmNPV-K1 v-cath differed at 4 amino acid positions from BmNPV T3. The v-cath gene in BmNPV-K1 genome is located on the EcoRV 6 kb and XhoI 9 kb fragments. Northern hybridization analysis of BmNPV K1 v-cath gene revealed that it is expressed late in infection.

• Korean Journal of Materials Research
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• v.31 no.9
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• pp.519-524
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• 2021

The impact properties of two austenitic Fe-23Mn-0.4C steels with different Al contents for cryogenic applications are investigated in this study. The 4Al steel consists mostly of austenite single-phase microstructure, while the 5Al steel exhibits a two-phase microstructure of austenite and delta-ferrite with coarse and elongated grains. Charpy impact test results reveal that the 5Al steel with duplex phases of austenite and delta-ferrite exhibits a ductile-to-brittle transition behavior, while the 4Al steel with only single-phase austenite has higher absorbed energy over 100 J at -196 ℃. The SEM fractographs of Charpy impact specimens show that the 4Al steel has a ductile dimple fracture regardless of test temperature, whereas the 5Al steel fractured at -100 ℃ and -196 ℃ exhibits a mixed fracture mode of both ductile and brittle fractures. Additionally, quasi-cleavage fracture caused by crack propagation of delta-ferrite phase is found in some regions of the brittle fracture surface of the 5Al steel. Based on these results, the delta-ferrite phase hardly has a significant effect on absorbed energy at room-temperature, but it significantly deteriorates low-temperature toughness by acting as the main site of the propagation of brittle cracks at cryogenic-temperatures.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.4
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• pp.185-192
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• 2022

Variations in the microstructure and mechanical properties of API X70 steel processed by piping, electrical resistance welding (ERW), and post seam annealing (PSA) are investigated in this study. In the welding zone, some elongated pearlites are formed and grains coarsening occurs due to extra heat caused by the ERW and PSA processes. After the piping, the base metal shows continuous yielding behavior and a decrease in yield and impact strengths because mobile dislocation and back stress are introduced during the piping process. On the other hand, the ERW and PSA processes additionally decreased the impact strength of welding zone at room and low temperatures because some elongated pearlites easily act as crack initiation site and coarse ferrite grains facilitate crack propagation. As a result, the fracture surface of the welding zone specimen tested at low temperature revealed mostly cleavage fracture unlike the base metal specimen.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.86-102
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• 1994

To understand the molecular structure and pathogenesis mechanism of Korean garlic viruses, we have isolate cDNA clones for garlic viruses. The partial nucleotide sequences of 24 cDNA clones were determined and that of six clones containing poly (A) tail were compared with those of other plant viruses. One of those clones, V9 has 81.8% similarity in nucleotide sequence and 93.0% in deduced amino acid sequence, respectively, to the coat protein gene for garlic mosaic virus (GMV). Northern blot analysis with the clone V9 demonstrated that the genome of GMV is 7.8 kb long and has poly (A) tail. The anti-coat protein antibody for GMV recognizes 35 kDa polypeptide which could be the coat protein of GMV from infected garlic leaf extract or virus preparation. Clone G7 has about 62% of deduced amino acid sequence identity with the members of potyvirus group. Northern blot analysis with the clone G7 demonstrated that the genome of the potyvirus I garlic is 9.0 kb long and has poly (A) tail. The third clone, S81, shows 42% amino acid identity to the potexvirus. The other clones are under the characterization. To test the possibility of producing garlic virus resistant plant, we have designed a hairpin type ribozyme to cleave V9 RNA at the middle of the coat protein gene. From the cleavage reactions in vitro with two different sizes of RNA substrates, V9SUB (144 nucleotides) and V9 RNA (1,361 nucleotides), the ribozyme can cleave V9 sequence effectively at the predicted site. To study the activity of the ribozyme in vivo, plant transformation is in progress. Further possibilities to produce garlic virus resistant plant will be discussed.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.19-19
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• 2001

Mammalian urothelium undergoes unique membrane specialization by making the asymmetric unit membrane (AUM) that is covered with the apical cell surface during terminal differentiation. The AUM contains several major integral membrane proteins including uroplakin Ia, Ib, II and III. The genes for uroplakins have been cloned from humans and mice, but not from porcine. In this study, we report the cloning of the UPII genomic DNA, which codes for the full length open reading frame for the uroplakin II protein. The deduced amino acid sequence encodes of a hydrophobic NH$_2$-terminal peptide, a prosequence, and a mature protein. The prosequence contains three potential N-glycosylation sites and a RGRR cleavage site that may be involved in uroplakin II processing and maturation. Northern and immunohistochemistry analyses showed that the porcine UPII gene is only expressed in urothelium and that the protein was specifically localized in urothelial superficial cells. A 2kb of upstream in the promoter sequence contains multiple transcription factor binding sites, including GC-box, SPI, AP2, and GATA-box sites, but not for TATA or CAAT-box sequences. Comparison of the porcine UPII promoter sequence with that of the murine by MEME system presented two conserved motifs, suggesting a cis-acting regulatory role for the conserved sequences. Sequence homology between two species in motif A and B was 79% and 80% respectively, although their relative locations were different. During the gestation, mouse bladder at estrus stages and day 10 after parturition showed higher UPII expression, while showed lower expression at peri-implantation stage. Taken together, our results showed that the porcine UPII gene was expressed highly and specifically in the bladder urothelium and that steroid hormones for implantation changed the expression of UPII in the bladder, although the biological significance of UPII remains to be not determined.

• Clinical and Experimental Vaccine Research
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• v.12 no.2
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• pp.156-171
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• 2023

Purpose: The development of vaccines that confer protection against multiple avian influenza A (AIA) virus strains is necessary to prevent the emergence of highly infectious strains that may result in more severe outbreaks. Thus, this study applied reverse vaccinology approach in strategically constructing messenger RNA (mRNA) vaccine construct against avian influenza A (mVAIA) to induce cross-protection while targeting diverse AIA virulence factors. Materials and Methods: Immunoinformatics tools and databases were utilized to identify conserved experimentally validated AIA epitopes. CD8⁺ epitopes were docked with dominant chicken major histocompatibility complexes (MHCs) to evaluate complex formation. Conserved epitopes were adjoined in the optimized mVAIA sequence for efficient expression in Gallus gallus. Signal sequence for targeted secretory expression was included. Physicochemical properties, antigenicity, toxicity, and potential cross-reactivity were assessed. The tertiary structure of its protein sequence was modeled and validated in silico to investigate the accessibility of adjoined B-cell epitope. Potential immune responses were also simulated in C-ImmSim. Results: Eighteen experimentally validated epitopes were found conserved (Shannon index <2.0) in the study. These include one B-cell (SLLTEVETPIRNEWGCR) and 17 CD8⁺ epitopes, adjoined in a single mRNA construct. The CD8⁺ epitopes docked favorably with MHC peptidebinding groove, which were further supported by the acceptable ∆G_bind (-28.45 to -40.59 kJ/mol) and Kd (<1.00) values. The incorporated Sec/SPI (secretory/signal peptidase I) cleavage site was also recognized with a high probability (0.964814). Adjoined B-cell epitope was found within the disordered and accessible regions of the vaccine. Immune simulation results projected cytokine production, lymphocyte activation, and memory cell generation after the 1st dose of mVAIA. Conclusion: Results suggest that mVAIA possesses stability, safety, and immunogenicity. In vitro and in vivo confirmation in subsequent studies are anticipated.

• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.101-108
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• 2008

The Agrobacterium-mediated transformation has been successfully used method to introduce foreign genes into some monocotyledonous as well as a large number of dicotyledonous plants genome, We developed transgenic Chinese cabbage plants with insect-resistance gene, modified CryIAc, by Agrobacterium-transformation and confirmed transgene copy number by Southern blot analysis. We confirmed that twenty-nine out of 46 transgenic Chinese cabbage plants have single copy of CryIAc. To obtain the sequences information on the transferred DNA (T-DNA) integration into plant genome, we analyzed left border (LB) flanking sequences by genome walking (GW) PCR method. Out of 46 transgenic Chinese cabbage plants examined, 37 carried the vector backbone sequences. This result indicates that the transfer of the vector backbone from the binary vectors resulted mainly from inefficient termination of LB site. Analysis of T-DNA LB flanking region of 9 transgenic Chinese cabbage plants without vector backbone revealed that all LB ends were not conserved and nucleotides up to 36bp from the LB cleavage site were deleted.