• BMB Reports
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• v.32 no.6
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• pp.561-566
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• 1999

CA(1-8)-ME(1-12) [CA-ME], composed of cecropin A(1-8) and melittin(1-12), is a synthetic antimicrobial peptide having potent antibacterial and antitumor activities with minimal hemolytic activity. In order to investigate the effects of the flexible hinge sequence, Gly-Ile-Gly, of CA-ME on antibiotic activity, CA-ME and three analogues, CA-ME1, CA-ME2, and CA-ME3, were synthesized. The Gly-Ile-Gly sequence of Ca-ME was deleted in CA-ME1 and replaced with Pro and Gly-Pro-Gly in CA-ME2 and CA-ME3, respectively. CA-ME1 and CA-ME3 showed a significant decrease in antitumor activity and phospholipid vesicle-disrupting ability. However, CA-ME2 showed similar antitumor and vesicle-disrupting activities, as compared with CA-ME. These results suggest that the flexibility or ${\beta}$-turn induced by Gly-Ile-Gly or Pro in the central part of CA-ME may be important in the electrostatic interaction of the N-terminus cationic ${\alpha}$-helical region with the cell membrane surface and the hydrophobic interaction of the C-terminus amphipathic ${\alpha}$-helical region with the hydrophobic acyl chains in the cell membrane. CA-ME3 exhibited lower antitumor and vesicle-disrupting activities than CA-ME and CA-ME2. This result suggests that the excessive ${\beta}$-turn structure caused by the Gly-Pro-Gly sequence in CA-ME3 seems to interrupt ion channel/pore formation in the lipid bilayer. We concluded that the appropriate flexibility or bilayer. We concluded that the appropriate flexibility or ${\beta}$-turn structure provided by the central hinge is responsible for the effective antibiotic activity of the antimicrobial peptides with the helix-hinge-helix structure.

• Food Science of Animal Resources
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• v.25 no.3
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• pp.340-343
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• 2005

The objective of this work was to study separation of short peptide (glycine-tyrosine) by using supported liquid membranes (SLMs) containing Aliquat as a cationic carrier, In the present investigation, the influence of pH of donor phase, concentrations of carrier and salt concentrations of acceptor phase on separation flux rate were investigated. Below pH 7.0 the flux rate was not affected by NaCl concentration or carrier concentration. However, the rate was increased significantly above pH 7.0. The rate with Hossain's SLM(H-SLM) containing $20\%$ Aliquat was about 3-fold higher with pH 9.0 at 0.25 M NaCl and 10-fold higher with pH 8.0 at 1.0 M NaCl than that with Duggan's SLM(D-SLM) containing $8\%$ Aliquat respectively. Furthermore, the rate with H-SLM was 10-fold higher at 1.0 M NaCl than the rate with 0.25 M NaCl, In conclusion, it would appear that the rate of separation was facilitated by using high salt concentrations together with high carrier concentrations above pH 7.0.

• Bulletin of the Korean Chemical Society
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• v.27 no.7
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• pp.1020-1024
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• 2006

In this report, we describe the synthesis of mono- and di-valent cationic $3\beta$ [L-Lysinamide-carbamoyl] cholesterol (K-Chol) derivatives by solid-phase peptide synthesis method and the characteristics of K-Chol/antisense oligodeoxynucleotide (ODN) complexes. K-Chol was able to interact with antisense ODNs electrostatically and constructed nanometer-sized complexes of 50-100 nm in diameter. The formation of K-Chol/antisense ODN complexes was demonstrated by non-denaturing polyacrylamide gel electrophoresis assay and atomic force microscopy. The cell-associated radioactivity was measured to monitor the cellular uptake of the complexes containing radioactive antisense ODNs using HL 60 cells.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1275-1280
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• 2015

Previously, we performed de novo RNA sequencing of Scolopendra subspinipes mutilans using high-throughput sequencing technology and identified several antimicrobial peptide candidates. Among them, a cationic antimicrobial peptide, scolopendrasin VII, was selected based on its physicochemical properties, such as length, charge, and isoelectric point. Here, we assessed the anticancer activities of scolopendrasin VII against U937 and Jurkat leukemia cell lines. The results showed that scolopendrasin VII decreased the viability of the leukemia cells in MTS assays. Furthermore, flow cytometric analysis and acridine orange/ethidium bromide staining revealed that scolopendrasin VII induced necrosis in the leukemia cells. Scolopendrasin VII-induced necrosis was mediated by specific interaction with phosphatidylserine, which is enriched in the membrane of cancer cells. Taken together, these data indicated that scolopendrasin VII induced necrotic cell death in leukemia cells, probably through interaction with phosphatidylserine. The results provide a useful anticancer peptide candidate and an efficient strategy for new anticancer peptide development.

• Bulletin of the Korean Chemical Society
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• v.20 no.9
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• pp.1073-1077
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• 1999

CRAMP, a 37-amino acid cationic antimicrobial peptide was recently deduced from the cDNA cloned from mouse femoral marrow RNA. In order to investigate the structure-activity relationship and functional region of CRAMP, CRAMP and its 18-mer overlapping peptides were synthesized by the solid phase method. CRAMP showed broad spectrum antibacterial activity against both Gram-positive and Gram-negative bacterial strains (MIC: 3.125-6.25 μM) but had no hemolytic activity until 50 μM. CRAMP was found to have a potent anticancer activity (IC50: 12-23 μM) against two human small cell lung cancer cell lines. Furthermore, CRAMP was found to display faster bactericidal rate in B. subtilis rather than E. coli in the kinetics of bacterial killing. Among 18-meric overlapping fragment peptides, only CRAMP (16-33) displayed potent antibacterial activity (MIC: 12.5-50 μM) against several bacteria with no hemolytic activity. Circular dichroism (CD) spectra anal-ysis indicated that CRAMP and its analogues will form the amphipathic α-helical conformation in the cell membranes similar to other antimicrobial peptides, such as cecropins and magainins.

• Proceedings of the Korean Biophysical Society Conference
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• 1999.06a
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• pp.33-33
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• 1999

Mastoparan B (MP-B), an antimicrobial cationic tetradecapeptide amide isolated from the venom of the hornet Vespa basalis, is an amphiphilic ${\alpha}$-helical peptide. In order to study the relationship between the structure and biological activity, we used the three analogues by replacing amino acids with alanine (4LysAla： 4MP-B, 12-LYsAla: 12MP-B, 9TrpAla: 9Mp-B).(omitted)

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.880-888
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• 2006

Pleurocidin, an $\alpha$-helical cationic antimicrobial peptide, was isolated from skin mucosa of winter flounder (Pleuronectes americamus). It had strong antimicrobial activities against Gram-positive and Gram-negative bacteria, but had very weak hemolytic activity. The Gly$^{13,17}\rightarrow$Ala analog (pleurocidin-AA) showed similar antibacterial activities, but had dramatically increased hemolytic activity. The bacterial cell selectivity of pleurocidin was confirmed through the membrane-disrupting and membrane-binding affinities using dye leakage, tryptophan fluorescence blue shift, and tryptophan quenching experiments. However, the non-cell-selective antimicrobial peptide, pleurocidin-AA, interacts strongly with both negatively charged and zwitterionic phospholipid membranes, the latter of which are the major constituents of the outer leaflet of erythrocytes. Circular dihroism spectra showed that pleurocidin-AA has much higher contents of $\alpha$-helical conformation than pleurocidin. The tertiary structure determined by NMR spectroscopy showed that pleurocidin has a flexible. structure between the long helix from $Gly^3$ to $Gly^{17}$ and the short helix from $Gly^{17}$ to $Leu^{25}$. Cell-selective antimicrobial peptide pleurocidin interacts strongly with negatively charged phospholipid membranes, which mimic bacterial membranes. Structural flexibility between the two helices may play a key role in bacterial cell selectivity of pleurocidin.

• Molecules and Cells
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• v.42 no.3
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• pp.262-269
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• 2019

The porcine myeloid antimicrobial peptide (PMAP), one of the cathelicidin family members, contains small cationic peptides with amphipathic properties. We used a putative lysozyme originated from the bacteriophage P22 (P22 lysozyme) as a fusion partner, which was connected to the N-terminus of the PMAP36 peptide, to markedly increase the expression levels of recombinant PMAP36. The PMAP36-P22 lysozyme fusion protein with high solubility was produced in Escherichia coli. The final purified yield was approximately 1.8 mg/L. The purified PMAP36-P22 lysozyme fusion protein exhibited antimicrobial activity against both Gram-negative and Grampositive bacteria (Staphylococcus aureus, Salmonella enterica serovar Typhimurium, Pseudomonas aeruginosa, and Bacillus subtilis). Furthermore, we estimated its hemolytic activity against pig erythrocytes as 6% at the high concentration ($128{\mu}M$) of the PMAP36-P22 lysozyme fusion protein. Compared with the PMAP36 peptide (12%), our fusion protein exhibited half of the hemolytic activity. Overall, our recombinant PMAP36-P22 lysozyme fusion protein sustained the antimicrobial activity with the lower hemolytic activity associated with the synthetic PMAP36 peptide. This study suggests that the PMAP36-P22 lysozyme fusion system could be a crucial addition to the plethora of novel antimicrobials.

• Journal of Microbiology and Biotechnology
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• v.29 no.5
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• pp.687-695
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• 2019

In a previous work, we performed de novo RNA sequencing of Allomyrina dichotoma using next generation sequencing and identified several antimicrobial peptide candidates based on transcriptome analysis. Among them, a cationic antimicrobial peptide, allomyrinasin, was selected bioinformatically based on its physicochemical properties. Here, we assessed the antimicrobial and anti-inflammatory activities of allomyrinasin against microorganisms and mouse macrophage Raw264.7 cells. Allomyrinasin showed antimicrobial activities against various microbes and decreased the nitric oxide production of the lipopolysaccharide-induced Raw264.7 cells. Furthermore, quantitative RT-PCR and ELISA revealed that allomyrinasin reduced cytokine expression levels in the Raw264.7 cells. We also identified inducible nitric oxide synthase, cyclooxygenase-2 expression, and $PGE_2$ production through western blot analysis and ELISA. We confirmed that allomyrinasin bound to bacterial cell membranes via a specific interaction with lipopolysaccharides. Taken together, these data indicate that allomyrinasin has antimicrobial and anti-inflammatory activities as exemplified in lipopolysaccharide-induced Raw264.7 cells. We have provided a potentially useful antimicrobial peptide candidate that has both antimicrobial and anti-inflammatory activities.

• Polymer(Korea)
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• v.30 no.4
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• pp.279-285
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• 2006

Non-viral gene carriers continue to attract a great deal of interest due to advantageous safety profile. Among the non-viral gene carriers, cationic liposomes or synthetic gene carriers are efficient DNA carriers in vitro. but their in vivo applications are greatly hampered because of low biocompatibility. On the other hand, chitosan, a natural cationic polysaccharide, is a candidate non-viral vector for gene delivery because of its low cytotoxicity and high positive charges. In this work, targeted gene carrier was synthesized to target artery wall cells using low molecular water-soluble chitosan (LMWSC). The molecular weight $(M_W)$ and degree of de acetylation (DDA) of LMWSC were measured by relative viscometer and Kina titration. respectively. The structure of LMWSC was analyzed by measuring FTIR, $^1H-NMR,\;and\;^{13}C-NMR$. AWBP-PEG-g-LMWSC was synthesized by conjugation of the artery wall binding peptide (AWBP), a specific targeting peptide, to the end of pegylated LMWSC as a gene carrier to target artery wall cells. The synthesized AWBP-PEG-g-LMWSC were analyzed by measuring FTIR, $^1H-NMR$, zeta -potentiometer, and atomic force microscopy (AFM).