• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3267-3274
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• 2014

In order to investigate the effects of the double replacement of $\small{L}$-Pro, $\small{D}$-Pro, $\small{D}$-Leu or Nleu (the peptoid residue for Leu) in the hydrophobic face (positions 9 and 13) of amphipathic ${\alpha}$-helical non-cell-selective antimicrobial peptide $L_8K_9W_1$ on the structure, cell selectivity and mechanism of action, we synthesized a series of $L_8K_9W_1$ analogs with double replacement of $\small{L}$-Pro, $\small{D}$-Pro, $\small{D}$-Leu or Nleu in the hydrophobic face of $L_8K_9W_1$. In this study, we have confirmed that the double replacement of $\small{L}$-Pro, $\small{D}$-Pro, or Nleu in the hydrophobic face of $L_8K_9W_1$ let to a great increase in the selectivity toward bacterial cells and a complete destruction of ${\alpha}$-helical structure. Interestingly, $L_8K_9W_1$-$\small{L}$-Pro, $L_8K_9W_1$-$\small{D}$-Pro and $L_8K_9W_1$-Nleu preferentially interacted with negatively charged phospholipids, but unlike $L_8K_9W_1$ and $L_8K_9W_1$-$\small{D}$-Leu, they did not disrupt the integrity of lipid bilayers and depolarize the bacterial cytoplasmic membrane. These results suggested that the mode of action of $L_8K_9W_1$-$\small{L}$-Pro, $L_8K_9W_1$-$\small{D}$-Pro and $L_8K_9W_1$-Nleu involves the intracellular target other than the bacterial membrane. In particular, $L_8K_9W_1$-$\small{L}$-Pro, $L_8K_9W_1$-$\small{D}$-Pro and $L_8K_9W_1$-Nleu had powerful antimicrobial activity (MIC range, 1 to $4{\mu}M$) against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Pseudomonas aeruginosa (MDRPA). Taken together, our results suggested that $L_8K_9W_1$-$\small{L}$-Pro, $L_8K_9W_1$-$\small{D}$-Pro and $L_8K_9W_1$-Nleu with great cell selectivity may be promising candidates for novel therapeutic agents, complementing conventional antibiotic therapies to combat pathogenic microorganisms.

• Biomedical Science Letters
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• v.2 no.2
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• pp.231-240
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• 1996

Human blood clotting (coagulation) factor 9 cDNA which codes for 461 amino acid has been cloned by screening human fetal liver cDNA library using PCR. This 1.4 kb cDNA spanning from the ATG initiation codon to the TAA termination codon was cloned into bacterial .expression vector pGEX-2T, generating pGEX-F9 plasmid. The plasmid pGEX-F9 expresses about 73 kDa GST (Glutathione S-transferase)-Factor 9 fusion protein when introduced into E. coli. Western blot analysis using polyclonal antibody raised against human factor 9 confirmed this fusion protein contains factor 9 protein. The level of GST-factor 9 expression was about 20% of total protein and the purification of fusion protein was efficiently achieved by using GST agarose bead based on one step purification protocol.

• Biomolecules & Therapeutics
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• v.17 no.2
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• pp.125-132
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• 2009

Calbindin-$D_{9k}$ (CaBP-9k), a cytosolic calcium-binding protein, is expressed in a variety of tissues, i.e., the duodenum, uterus, placenta, kidney and pituitary gland. Duodenal CaBP-9k is involved in intestinal calcium absorption, and is regulated at transcriptional and post-transcriptional levels by 1,25-dihydroxyvitamin D3, the hormonal form of vitamin D, and glucocorticoids (GCs). Uterine CaBP-9k has been implicated in the regulation of myometrial action(s) through modulation of intracellular calcium, and steroid hormones appear to be the main regulators in its uterine and placental regulation. Because phenotypes of CaBP-9k-null mice appear to be normal, other calcium-transporter genes may compensate for its gene deletion and physiological function in knockout mice. Previous studies indicate that CaBP-9k may be controlled in a tissue-specific fashion. In this review, we summarize the current information on calcium homeostasis related to CaBP-9k gene regulation by GCs, vitamin D and its receptors, and its molecular regulatory mechanism. In addition, we present related data from our current research.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.90-90
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• 2003

Circling mice were recorded to display profound deafness and a head-tossing and bidirectional circling behavior, showing an autosomal recessive mode of inheritance. In addition, the histological examination of inner ears revealed that the region around organ of Corti, spiral ganglion neurons and outer hair cells showed definite abnormality. On the other hand, a genetic linkage map was constructed in an intraspecific backcross between cir and C57BL/6J mice. The cir gene was mapped to a region between D9Mitl16/D9Mit15 and D9Mit38 on the mouse chromosome 9. Estimated distances between cir and D9Mitl16, and between cir and D9Mit38 are 0.70 $\pm$ 0.40 and 0.23 $\pm$ 0.23 cM, respectively. The markers in order was defined as follows: centromere-D9Mit182- D9Mit51/ D9Mit79/ D9Mit310- D9Mit212/ D9Mit184- D9Mit116/ D9Mit15- cir- D9Mit38- D9Mit20- D9Mit243- D9Mit16- D9Mit55/ D9Mit125- D9Mit281 Based on genetic mapping, we constructed for a YAC contig across cir region. They covered the entire region or cir and cir gene was located on between the lactotransferrin (ltf) and the macrotubule-associated protein (map4). It is known that sr gene is localized in 64cM of mouse chromosome 9. The two mouse were found to be allelic by complementation test. Recently the spinner mouse has been mapped to our cir region, and tmie gene were elucidated. And further study will be needed in circling mouse to prove tmie gene mutaiton.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.48-48
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• 2001

A new neurological mutant has been found in the ICR outbred strain mouse. Affected mice display profound deafness and a head-tossing and bidirectional circling behavior, showing an autosomal recessive mode of inheritance. It was, therefore, named cir/Kr with the gene symbol cir. The auditory tests identified clearly the hearing loss of the cir mice when compared to wild type mice. Pathological studies confirmed the developmental defects in the middle ear, cochlea, cochlear nerve, and semicircular canal areas, which were correlated to the abnormal behavior observed in the cir mice. Thus, cir mice may be useful as a model for studying inner ear abnormalities and deafness. We have constructed a genetic linkage map by positioning 14 microsatellite markers across the (cir) region and intraspecific backcross between cir and C57BL/6J mice. The cir mouse harbors an autosomal recessive mutation on mouse chromosome 9. The cir gene was mapped to a region between D9Mit116 and D9Mit38 Estimated distances between cir and D9Mit116, and between cir and D9Mit38 are 0.7 and 0.2 cM, respectively. The gene in order was defines : centromere-D9Mit182-D9Mit51/D9Mit79/D9Mit310-D9Mit212/D9Mit184-D9Mit116-cir-D9Mit38-D9Mit20-D9Mit243-D9Mit16-D9Mit55/D9Mit125-D9Mit281. The mouse map location of the cir locus appears to be in a region homologous to human 3q21. Our present date suggest that the nearest flanking marker D9Mit38 provides a useful anchor for the isolation of the cir gene in a yeast artificial chromosome contig.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.820-825
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• 1999

A bacterial strain WN9, which produced a new type of extracellular polysaccharide, was isolated from soil samples. By morphological, physiological, biochemical, and phylogenetic studies, strain WN9 was identified as a Paenibacillus sp. and it was named as Paenibacillus sp. WN9, which produced a high molecular extracellular polysaccharide from glucose. The molecular weight of the exopolysaccharide (EPS-WN9) was estimated to be about 31.5 mega-Da. The FT-IR spectrum of EPS-WN9 revealed typical characteristics of polysaccharides. EPS- WN9 consisted of D-glucose and D-mannose with a molar ratio of 1:1.4 being identified as a neutral sugar component. The acidic component of EPS- WN9 was tyrosine. Rheological analysis of EPS- WN9 revealed that the pseudoplastic property and its apparent viscosity remained stable at various temperatures and pHs.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.724-727
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• 2002

2,7-dibromo-9, 9-dialkyl-substituted-fluorene derivatives were prepared by the alkylation of 2,7-dibromofluorene with various alkyl groups under two-phase phase transfer catalysis (PTC) conditions, as monomers for synthesizing poly(dialkylfluorene)s. Tetra-nbutylammonium hydrogen sulfate (TBAHS) was used as a phase transfer catalyst to enhance nucleophilic substitution. In addition, NaOH in water (25M) was used as a base to generate anions. Compared to conventional alkylation using butyllithium(BuLi), the reaction using the PTC technique attained high selectivity and substantial conversion of reactants, due to the enhanced reaction rate, while the reaction was carried out under moderate conditions. An approximately 90% yield was obtained from the reaction and the reaction time was remarkably reduced. 2,7-dibromo-9,9-dihexyl-fluorene, 2,7-dibromo-9,9-dioctyl-fluorene, and 2,7-dibromo-9,9-di(2-ethylhexyl)-fluorene were effectively synthesized by phase transfer catalytic reaction.

• The KIPS Transactions:PartC
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• v.9C no.4
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• pp.573-580
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• 2002

Within the security architecture of the 3GPP system there is a standardised integrity algorithm f9. The integrity algorithm f9 computes a MAC to authenticate the data integrity and data origin of signalling data over a radio access link of W-CDMA IMT-2000. f9 is a variant of the standard CBC MAC based on the block cipher KASUMI. In this paper we provide the provable security of f9 We prove that f9 is secure by giving concrete bound on an adversary's inability to forge in terms of her inability to distinguish the underlying block cipher from a pseudorandom permutation.

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2809-2812
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• 2014

The 43-residue defensin-like peptide coprisin, which is isolated from dung bettle, Copris tripartitus, is a potent antimicrobial peptide. In our previous work, we determined the tertiary structure of coprisin and found that alpha helical region of coprisin from residue 19 to residue 30 is important for its antimicrobial activities. Here, we designed cop12mer and cop9mer analogs of coprisin based on the tertiary structure of coprisin. To investigate the relationship between hydrophobicity and antimicrobial activities and develop the potent peptide antibiotics, we designed cop9mer-1 with substitution of $His^2$ with Trp in cop9mer. The results showed that cop9mer-1 has higher toxicities as well as improved antimicrobial activities compared to cop9mer. In order to reduce the toxicity of cop9mer-1, we designed cop9mer-2 and cop9mer-3 with substitution of $Cys^3$ with Lys or Ser. Substitution of $Cys^3$ with these hydrophilic amino acids results in lower cytotoxicities compared to cop9mer-1. Cop9mer-2 with substitution of $Cys^3$ with Lys in Cop9mer-1 showed high antibacterial activities against drug resistant bacteria without cytotoxicity. Antibiotic action of cop9mer-1 analog appears to involve permeabilization of the bacterial cell membrane while cop9mer-2 and cop9mer-3 may have different mechanism of action. These results imply that that optimum balance in hydrophobicity and hydrophilicity in these 9-meric peptides plays key roles in their antimicrobial activities as well as cytotoxicities.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.216-222
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• 2003

Human caspase-9, an essential apoptosis initiator protease, was excessively degraded when expressed in Escherichia coli under the conventional induction condition. To optimize the conditions for induction and develop a rapid purification method for obtaining significant amounts of wild-type procaspase-9, we expressed procaspase-9 as GST fusion in E. coli. The addition of 0.01 mM IPTG as an inducer to the bacterial culture and decreasing the culture temperature to 25oC improved the production of procasapse-9 protein by circumventing proteolytic degradation in E. coli. The wild-type procaspae-9 was purified to approximately 70% purity with relatively high yields using the method developed in this study. In addition, we found that GST-caspase-9 is autocatalytically cleaved after aspartic acid 315, which is the same site for processing in mammalian cells, during expression in E. coli.