• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.439-445
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• 2021

Coccidiosis in chickens is an intestinal parasitic disease caused by protozoan parasites named Eimeria spp. In some Eimeria infections, intestinal lymphocytes are known to highly express chicken NK-lysin (cNK-lysin), an antimicrobial peptide with anticoccidial activity. Therefore, this study aims to investigate the expression of cNK-lysin in E. necatrix-infected chickens and its role in E. necatrix infection. The expression of cNK-lysin transcript was significantly increased in E. necatrix sporozoites-treated lymphocytes. In E. necatrix infection, cNK-lysin transcript was induced in intestinal lymphocytes but not in the spleen. The recombinant cNK-lysin exhibited anticoccidial activity against E. necatrix sporozoites as well as immunomodulatory activity on macrophages by inducing proinflammatory cytokines. These results indicated that E. necatrix infection induces high local expression of cNK-lysin and the secreted cNK-lysin helps protect coccidiosis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.8 no.1
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• pp.21-24
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• 1979

A study was made to investigate the effect of L-lysine fortification on the quality of rice protein by albino rat-feeding trials. Five subjects fed diets providing 1) rice protein only, 2) rice protein+0.25% L-lysin HCI, 3) rice protein+0.5% L-lysin HCI, 4) rice protein+0.75% L-lysin HCI and 5) rice protein+1.0% L-lysin HCI for 28 days respectively. Protein efficiency ratio(PER) indicated that 0.25% lysine fortified diet had highest value. Lower PER values were shown in the higher fortified diets(0.5% through 1.0% L-lysine) comparing to 0.25% fortified diet. However, there was no adverse effect on the protein quality by the given fortificaton level($0{\sim}1.0%$ L-lysin HCI addition).

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.783-792
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• 2014

The binding interaction between a hemolytic peptide ${\delta}$-lysin and a zwitterionic lipid bilayer POPC was investigated through a series of molecular dynamics (MD) simulations. ${\delta}$-Lysin is a 26-residue, amphipathic, ${\alpha}$-helical peptide toxin secreted by Staphylococcus aureus. Unlike typical antimicrobial peptides, ${\delta}$-lysin has no net charge and it is often found in aggregated forms in solution even at low concentration. Our study showed that only the monomer, not dimer, inserts into the bilayer interior. The monomer is preferentially attracted toward the membrane with its hydrophilic side facing the bilayer surface. However, peptide insertion requires the opposite orientation where the hydrophobic side of peptide points toward the membrane interior. Such orientation allows the charged residues, Lys and Asp, to have stable salt bridges with the lipid head-group while the hydrophobic residues are buried deeper in the hydrophobic lipid interior. Our simulations suggest that breaking these salt bridges is the key step for the monomer to be fully inserted into the center of lipid bilayer and, possibly, to translocate across the membrane.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.38-43
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• 2016

Novel and specific recognition elements are of central importance in the development of a pathogen detection method. Here, we describe a simple method for identifying the cell-wall binding domain (CBD) from a sequenced bacterial genome employing homology search for phage lysin genes. A putative CBD (CPF369_CBD) was identified from a genome of Clostridium perfringens type strain ATCC 13124, and its function was studied with the CBD-GFP fusion protein recombinantly expressed in Escherichia coli. Fluorescence microscopy showed the specific binding of the fusion protein to C. perfringens cells, which demonstrates the potential of this method for the identification of novel bioprobes for specific detection of pathogenic bacteria.

• Membrane Journal
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• v.6 no.2
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• pp.96-100
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• 1996

In order to improve the permeability of the homogenous membrane of poly(carbobenzoxy-L-lysin)(PCLL), which has very high selectivity of helium gas to nitrogen gas, asymmetric porous membranes of PCLL were prepared by casting from 20% solutions in dioxane and dimethylformamide(DMF), respectively. The membranes were characterized by measuring the number of the pores, the pore size distribution of the surface(the skin layer) and the thickness of the skin layer by scanning electron microscope and transmission electron microscope. The mean pore size and the pore density were lower for the membrane cast from dioxane than that from DMF, which was explained by the mechanism of the formation of the pores in the asymmetric porous membrane. The permeability coefficient observed could be roughly explained by the viscous flow through the skin layer. However, the selectivity observed was against the theory of the viscous flow.

• Journal of Pharmaceutical Investigation
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• v.34 no.6
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• pp.491-497
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• 2004

We investigated some important factors which affect the transdermal flux of ketoprofen, a nonsteroidal anti-inflammatory agent, as a first step to provide some basic knowledge for the development of a iontophoretic transdermal patch system. Factors such as current density, polarity, buffer (HEPES) and electrolyte concentration and pH were studied using hairless mouse skin. The effect of poly(L-lysin), which is known to affect the electro-osmotic flow through skin, on flux was also studied. Passive flux was about $20\;{\mu}g/cm^2hr$ at pH 4.0, but was negligible at pH 7.4 where all ketoprofen molecules dissolved are ionized (ketoprofen pKa=5.94). At pH 4.0, application of anodal current increased the flux further above the passive level, however anodal flux at pH 7.4 was much smaller than passive flux at pH 4.0. The application of cathodal current at pH 4.0 increased the average flux to $30-40\;{\mu}g/cm^2hr$, depending on the current density applied. At pH 7.4, cathodal flux was only about $5\;{\mu}g/cm^2hr$. Decrease in buffer and electrolyte concentration increased this cathodal flux about 10 fold. However decrease in HEPES buffer concentration 100 fold did not affect the flux. Anodal flux of acetaminophen was much larger than cathodal flux, indicating that electroosmotic flow can be playing an important role in the flux. Poly(L-lysin) increased the cathodal flux at pH 7.4. These results provide some important insights into the mechanism of transdermal flux of ketoprofen and the role of electroosmotic flow.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.69-77
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• 2022

Antimicrobial peptides (AMPs) play an important role in innate immunity against pathogenic infections. AMPs exterminate pathogenic bacteria by disrupting cell membranes or inhibiting intracellular molecules. NK-2, first identified in pigs and derived from NK-lysin, has antimicrobial effects against bacteria and parasites. In this study, chimeric peptides (cpNK) of chicken and pig NK-2 and cpNK-derived peptides (cpNK-a1 and cpNK-a2) were synthesized, and their antimicrobial effects against various pathogenic bacteria such as Escherichia coli, Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA) were investigated. The structure of chimeric peptides from chicken and pig NK-2, cpNK, include α-helix like NK-2 and peptide net charge was +9 like porcine NK-2. The cpNK peptide showed powerful bactericidal effects against most bacterial species, including MRSA, especially against gram-negative bacteria. Furthermore, cpNK-derived short peptides, cpNK-a1 and a2 also showed bactericidal activity, but the effects were weaker than those of cpNK. Therefore, we conclude that cpNK- and cpNK-derived short peptides have the potential to be used as antibiotic alternatives.

• Journal of Plant Biotechnology
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• v.38 no.2
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• pp.176-185
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• 2011

Rice is one of the most important crop in the world, in particular for food resources. With its small genome size of 383 Mb, the Oryza sativa is a model plant for genome research. Indeed, it's grain provides human with a source of carbohydrates and proteins. Rice grain has relatively low protein contents (around 8%) compared to other legume seeds (around 40%). Osborne classified seed proteins into water soluble albumin, salt soluble globulin, alcohol soluble prolamin and acidic/alkaline solution soluble glutelin. Glutelin and prolamin are the major storage proteins in rice. For the gene expression study of seed storage proteins, we analyzed 33,192 EST clones at immature stages in a rice cultivar (Oryza sativa L. cv. 'Ilpum'). Based on the expression analysis, we cloned 11 glutelin genes and figured out the 8 genes are located on Chromosome 2. The expression of glutelin genes appears to be about 28.2% of total level in immature seeds. Interestingly, glu-04 is duplicated as inverted sequences on the same chromosomes as far 4.5 kb. Our results indicate that glutelin genes, evolutionarily, were replicated on the chromosome and thus expressed as specific manners. In a whole protein composition analysis, glu05 (type B7) contains the highest lysin contents (4.51%) among the 11 rice glutelin genes. It will be an interesting future work to increase lysin contents by the gene overexpressor strategy with the aim of improved diet nutritionally fortified.

• Journal of the Korean Home Economics Association
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• v.23 no.1
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• pp.25-31
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• 1985

This study designed not only to elucidate free amino acid, fatty acid composition and mineral content in dried alaska pollack but also to examine calcium, magnesium, poassium and sodium contents in its cooking broth according to each boiling time such as 2.5, 5, 10, 20, and 30 minutes. RESULTS : 1. Glutamic acid in dried alaska pollack was the most abundant free amino acid and was followed in order of aspartic acid, lysin, leucine and histidine. They composed of 50.95% of the total amino acid contents. 2. In dried alaska pollack the most abundant fatty acid was palmitic acid. Essential fatty acid content was 26.57% of the total fatty acid. 3. The calcium, magnesium, potassium and sodium contents in dried alaska pollack showed 10.721 mg%, 9.235mg%, 4072.5mg% and 2299.8% respectively. The amount of magnesium and potassium in cooking broth arrived at the highest level when 20 minute boiling was undertaken and the quantities of magnesium and sodium were the highest when 30 minute boiling was made.

• Korean Journal of Veterinary Research
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• v.22 no.1
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• pp.15-21
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• 1982

The biochemical properties of strains of Staphylococcus aureus isolated from cattle with peracute gangrenous mastitis, acute systemic mastitis and chronic mastitis were examined. Of 261 strains of Staphylococci isolated from quarters with clinical mastitis, 140 (53.6%) were classified as Staphylococcus aureus and 121 (46.4%) were coagulase-negative staphylococci. All the strains of Staphylococcus aureus isolated from quarters with peracute gangrenous mastitis and acute systemic mastitis showed production of alpha heamolysin, coagulase, lipase, phosphatase, nuclease and gelatinase, and fermentation of mannitol. However, of 114 strains of Staphylococcus aureus obtained from quarters with chronic mastitis, 64 (56.1%) possessed alpha lysin, and 43 (37.7%) produced lipase in egg yolk medium. The most common hemolytic pattern of the strains associated with chronic mastitis was ${\beta}{\delta}$ type.