• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.807-812
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• 2002

In order to analyze the cellular proteins which interact with core protein of hepatitis C virus (HCV), a yeast two-hybrid screening technique was employed. A carboxyl terminus truncated core protein, which contained amino acid residues from the 1st to 120th, was used as a bait to screen cellular proteins. The expression library prepared from HeLa cell was screened and 400 positive clones were selected. The 75 clones from the positive clones were sequenced and analyzed by undergoing the Blast search. Interestingly, 7 out of the 75 clones encoded E7 antigen of human papilloma virus (HPV). We studied in detail the Interaction between the truncated version of HCV core and E7 antigen in vitro. The core$_{120}$ protein expressed in chimeric form with G57 was able to bring down the E7 protein of HPV type 18 expressed in bacteria. It is therefore suggested that the core of HCV might affect the interaction between E7 and a normal cellular tumor suppressor, known as Rb protein.

• Korean Journal of Microbiology
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• v.5 no.2
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• pp.61-68
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• 1967

In the process of the incorporation of orthophsphate into protein and other cell constituents, the role of inorganic polyphosphate and RNA-polyphosphate complex and the correlation between them were pursued by analyzing the contents of $^{32}P$ and total P in various fractions of Chlorella cells, which had been uniformly labeled with $^{32}P$ before the inoculation in a normal "cold" medium or P-free medium during the culture. The effects of ionizing radiation and various micronutritional-element deficiencies on the phosphate incorporation into, and biosynthesis of, protein and other introgenus compounds in the cells were also observed. When the uniformly $^{32}P$-labeled algae were grown in a normal "cold" medium the contents of $^{32}$ P in the fractions of protein, DNA and RNA-polyphosphate complex increased, but those in the fraction of acid-insoluble polyphosphate decreased. On the other hand, amount of $^{32}P$in the fraction of RNA was almost unchanged in spite of rapid increase of the total P. In the growing period of $^{32}P$-labeled algae in a P-free medium, amounts of $^{32}P$ in the fractions of DNA, protein and lipid increased, while those in the fractions of RNA-polyphosphate and inorganic polyphosphates decreased. When the algal cells were irradiated with about 70, 000r of gamma-rays before the inoculation in the medium, amounts of phosphate in the fractions of DNA, RNA, nucleotides and protein decreased during the culture, compared with those of the control. However, the phosphate content in the fraction of acid-insoluble polyphosphate of the irradiated cells increased than those of the control. In the growing period of the algae in a Mo-free, medium, amounts of acid-soluble total phosphate and nucleotides of the cells increased, while the amounts of residual protein and RNA decresed compared with those of the normal cells. Amounts of alkali-labile protein and phospholipid of the cells grown in a B-free medium decreased, whereas amount of phosphate in acid-soluble fraction increased compared with the control. In general, the contents of protein and RNA in each microelement deficient cells decreased more or less, compared with those in the normal cells.in the normal cells.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.2
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• pp.85-94
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• 2002

Antibodies raised against the purified p-subunit of $\beta$-conglycinin were used in immunohistochemical studies to monitor the pattern of $\beta$-conglycinin mobilization in the cotyledons during soybean [Glycine max (L.) Merr.] seed germination. Western blot analysis revealed that the break down of the $\beta$-subunit of $\beta$-conglycinin commenced as early as 2 days after seed imbibition (DAI). Concurrent with the degradation of the $\beta$-subunit of $\beta$-conglycinin, accumulation of 48, 28, and 26 kD proteolytic intermediates was observed from 2 to 6 DAI. Western blot analysis also revealed that the acidic subunit of glycinin was mobilized earlier than the basic subunit. The basic glycinin subunit was subjected to proteolysis within 2 DAI resulting in the appearance of an intermediate product approximately 2 kD smaller than the native basic glycinin subunit. In contrast to the major seed storage proteins, lipoxygenase was subjected to limited proteolysis and was detected even after 8 DAI. The first sign of $\beta$-conglycinin breakdown was observed near the vascular strands and proceeded from the vascular strands towards the epidermis. Protein A-gold localization studies using thin sections of soybean cotyledons and antibodies raised against the $\beta$-subunit of $\beta$-conglycinin revealed intense labeling over protein bodies. A pronounced decrease in the protein A-gold labeling intensity over protein bodies was observed at later stages of seed germination. The protein bodies, which were converted into a large central vacuole by 8 DAI, contained very little 7S protein as evidenced by sparse protein A-gold labeling in the vacuoles.

• Kidney Research and Clinical Practice
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• v.37 no.4
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• pp.384-392
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• 2018

Background: A very low protein diet (VLPD) with ketoacid analogs of essential amino acids (KA/EAA) administration can remarkably influence protein synthesis and metabolic disturbances of patients with advanced chronic kidney disease (CKD), and may also slow the decline in renal function. Methods: A retrospective cohort study was carried out to monitor renal progression and metabolic and nutritional status among 140 patients with CKD stage III or IV. One group (n = 70) was on a low protein diet (LPD) with 0.6 g of protein intake, and another group (n = 70) was on a VLPD with 0.3 g of protein and KA/EAA supplementation of 100 mg/kg/day for 12 months. Results: At 12-month follow-up, estimated glomerular filtration rate (GFR) significantly decreased from $41.6{\pm}10.2$ to $36.4{\pm}8.8mL/min/1.73m^2$ (P < 0.001) and urine protein increased from $0.6{\pm}0.5$ to $0.9{\pm}1.1g/day$ (P = 0.017) in the LPD group, but no significant changes in estimated GFR and urine protein were found in the VLPD plus KA/EAA group. A significant mean difference in rate of change in estimated GFR ($-5.2{\pm}3.6mL/min/1.73m^2$ per year; P < 0.001) was observed between the two groups. After Cox regression analysis, treatment with VLPD plus KA/EAA significantly protected against the incidence of declining GFR > 10% annually (adjusted hazard ratio, 0.42; 95% confidence interval, 0.23-0.79; P = 0.006) and significant correlations were found between using VLPD plus KA/EEA and increased GFR. Conclusion: VLPD supplementation with KA/EAA is associated with delayed renal progression while preserving the nutritional status in the patients with CKD. Co-administration of VLPD and KA/EAA may prove an effective alternative to conservative management of CKD.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.272-278
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• 1998

This study was carried out to investigate the functional properties such as nitrogen solubility, emulsifying property , foaming capapcity , water and oil absorption of Camellia (Camellia japonica .) seed protein isolate in condition of distilled water and 0.5M NaCl solution at pH 2.0∼10.0. Nitrogen solubility of Camellia protein isolate in distilled water showed the minimum value at pH 4.0 and increased at pH lower or higher than the isoelectric point(pH 4.0). It was 90.0 %at pH 10.0 Nitrogen solubility of 0.5M NaCl solution showed a similar pattern with that of distrille dwater but was higher than that of distilled water except pH 2.0 and pH 10.0. Emulsifying activity of Camellia seed protein islate showed the minimum value at pH 4.0, but was higher at ether value of pH. Emulsifying stability of protein isolate was stable by heat treatment for 30min, at 80℃ and increased in 0.5M NaCl solution more than that of distille dwater. Foaming capacity of Camellia seed protein isolate in distill3ed water showed the minimum value near the isoelectric point, While it changed little at other values of pH. Foaming stability slowly decreased as, but didn't make a significant difference as time was delayed . Oil absorption was 1.4ml per a sample of 1g and water absorption was 0.9ml per a sample of 1g. The former was higher than the latter . The content of total amino acid of Camellia protein isolate was 43.67% and the major total amino acid of Camellia protein isolate was 43.67% and the major total amino acid was in the order of glutamic acid , arginine, aspartic acid, and leucine.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.268-268
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• 2022

Protein is a major nutrient of food and has long been studied for nutritional and utility value. Among them, rice protein is attracting attention because of its hypoallergenic characteristics and nutritional value. Mutant DM225 with increased protein content was selected by EMS treatment on the weed rice Dharial. QTL analysis of Protein content was carried out using BC₂F₂ populations derived from a cross between "Hanareum2" as a recurrent parent and "DM225" as a donor parent. The protein content of populations was between 5~11%, with an average of 7.7%. To identify QTLs related to Protein content, 117 KASP markers(polymorphic ratio: 15%) showing polymorphisms between the parents were genotyped for the BC₂F₂ population. One QTL was detected between markers SK07 06 and SK07_10 on chromosome 7(LOD: 28.1). This QTL explained 71.4% of the phenotypic variance for Protein content. This QTL will be useful for protein-related rice breeding program.

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.118-120
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• 2002

Genetic materials including DNA plasmid are effective delivery vehicle to express interesting gene efficiently and safely not to generate replication competent virus. Moreover, it has advantages to design a better vector and to simplify manufacturing and storage condition. To understand a possible pathogenic mechanism by a flavivirus, West Nile virus (WNV), WNV genome sequence was aligned to other pathogenic viral genome. Interestingly, WNV capsid (Cp) amino acid sequence has some homology to HIV-l Vpr protein. These proteins induce apoptosis in human cell lines as well as in vivo and cell cycle arrest. Therefore, DNA plasmid carrying apoptosis-inducing and cell cycle arresting viral proteins including a HIV-1 Vpr and a WNV Cp protein can be useful for anti-cancer therapeutic applications. This WNV Cp protein is an early expressed protein which can be a reasonable target antigen (Ag) for vaccine design. Immunization of a DNA construct encoding WNV Cp protein induces a strong Ag-specific humoral and Th1-type immune responses in animal. Therefore, DNA plasmid encoding apoptotic viral proteins can be useful tool for therapeutic and prophylactic applications.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2001.06a
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• pp.83-89
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• 2001

Recent advances in the structural and molecular biology uncovered that a set of translation factors resembles a tRNA shape and, in one case, even mimics a tRNA function for deciphering the genetic ：ode. Nature must have evolved this 'art' of molecular mimicry between protein and ribonucleic acid using different protein architectures to fulfill the requirement of a ribosome 'machine'. Termination of protein synthesis takes place on the ribosomes as a response to a stop, rather than a sense, codon in the 'decoding' site (A site). Translation termination requires two classes of polypeptide release factors (RFs)： a class-I factor, codon-specific RFs (RFI and RF2 in prokaryotes; eRFI in eukaryotes), and a class-IT factor, non-specific RFs (RF3 in prokaryotes; eRF3 in eukaryotes) that bind guanine nucleotides and stimulate class-I RF activity. The underlying mechanism for translation termination represents a long-standing coding problem of considerable interest since it entails protein-RNA recognition instead of the well-understood codon-anticodon pairing during the mRNA-tRNA interaction. Molecular mimicry between protein and nucleic acid is a novel concept in biology, proposed in 1995 from three crystallographic discoveries, one, on protein-RNA mimicry, and the other two, on protein-DNA mimicry. Nyborg, Clark and colleagues have first described this concept when they solved the crystal structure of elongation factor EF- Tu：GTP：aminoacyl-tRNA ternary complex and found its overall structural similarity with another elongation factor EF-G including the resemblance of part of EF-G to the anticodon stem of tRNA (Nissen et al. 1995). Protein mimicry of DNA has been shown in the crystal structure of the uracil-DNA glycosylase-uracil glycosylase inhibitor protein complex (Mol et al. 1995; Savva and Pear 1995) as well as in the NMR structure of transcription factor TBP-TA $F_{II}$ 230 complex (Liu et al. 1998). Consistent with this discovery, functional mimicry of a major autoantigenic epitope of the human insulin receptor by RNA has been suggested (Doudna et al. 1995) but its nature of mimic is. still largely unknown. The milestone of functional mimicry between protein and nucleic acid has been achieved by the discovery of 'peptide anticodon' that deciphers stop codons in mRNA (Ito et al. 2000). It is surprising that it took 4 decades since the discovery of the genetic code to figure out the basic mechanisms behind the deciphering of its 64 codons.

• Biomolecules & Therapeutics
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• v.11 no.3
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• pp.157-162
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• 2003

The generation of secretory IgA antibodies(Abs) for specific immune protection of mucosal surfaces depends on stimulation of the mucosal immune system, but this is not effectively achieved by parenteral or even oral administration of most soluble antigens. Thus, to produce a possible vaccine antigen against urinary tract infections, the uropathogenic E. coli (UPEC) adhesin was genetically coupled to the ctxa2b gene and cloned into a pMAL-p2E expression vector. The chimeric construction of pMALfimHIctxa2b was then transformed into E. coli K-12 TB1 and its nucleotide sequence was verified. The chimeric protein was then purified by applying the affinity chromatography. The purified chimeric protein was confirmed by SDS-PAGE and western blotting using antibodies to the maltose binding protein (MBP) or the cholera toxin subunit B (CTXB), plus the N-terminal amino acid sequence was analyzed. The orderly-assembled chimeric protein was confirmed by a modified $G_{M1}$-ganglioside ELISA using antibodies to adhesin. The results indicate that the purified chimeric protein was an Adhesin/CTXA2B protein containing UPEC adhesin and the $G_{M1}$-ganglioside binding activity of CTXB. This study also demonstrate that peroral administration of this chimeric immunogen in mice elicited high level of secretory IgA and serum IgG Abs to the UPEC adhesin. The results suggest that the genetically linked CTXA2B acts as a useful mucosal adjuvant, and that the adhesin/CTXA2B chimeric protein might be a potential antigen for oral immunization against UPEC.

• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.325-332
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• 1998

In vitro phosphorylation experiments with a cell extract of Streptomyces coelicolor A3(2) M130 in the presence of ${\gamma}-[^32P]$]ATP revealed the presence of multiple phosphorylated proteins, including the AfsR/AfsK kinases which control the biosynthesis of A-factor, actinorhodin, and undecylprodigiosin. Phosphorylation of AfsR by a cell extract as an AfsK source was significantly inhibited by Ser/Thr protein kinase inhibitors, staurosporine and K-252a, at concentrations giving 50% inhibition ($IC_50$) of $1{\mu}M\;and\;0.1{\mu}M$, respectively. Further in vitro experiments with the cell extracts showed that phosphorylation of multiple proteins was inhibited by various protein kinase inhibitors with different inhibitory profiles. Manganese and calcium ions in the reaction mixture also modulate phosphorylation of multiple proteins. Manganese at 10 mM greatly enhanced the phosphorylation and partially circumvented the inhibition caused by staurosporine and K-252a. A calcium-activated protein kinase(s) was little affected by these inhibitors. Herbimycin and radicicol, which are known as tyrosine kinase inhibitors, did not show any significant inhibition of AfsR phosphorylation. Consistent with the in vitro effect of the kinase inhibitors, they inhibited aerial mycelium formation and pigmented antibiotic production on solid media. On the contrary, when assayed in liquid culture, the amount of actinorhodin produced was increased by staurosporine and K-252a and greatly decreased by manganese. All of these data clearly show that the genus Streptomyces possesses several protein kinases of eukaryotic types which are involved in the regulatory network for morphogenesis and secondary metabolism.