• Journal of Life Science
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• v.12 no.1
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• pp.14-18
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• 2002

Subpopulations of nucleotides that bind specifically to a variety of proteins have been isolated from a population of random sequence RNA/DNA molecules. Roughly one in $10^{13}$ random sequence RNA/DNA molecules folds in such a way as to create a specific binding site for small ligands. Since the development of in vitro selection procedure, more than 50 nucleic acid ligands (aptamers) have been isolated. These molecules are very useful for the study of molecular recognition between nucleic acid and protein/organic compound. In addition to these basic studies this method gives us a dream to produce new drugs against several diseases. We focused on several aptamers which specifically binds to trypsin-like serine proteases (thrombin, human neutrophil elastase, activated protein C and NS3 protease of human hepatitis C virus) and want to introduce their structural characteristics and some functions.

• The Journal of Internal Korean Medicine
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• v.13 no.2
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• pp.126-133
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• 1992

Comparative amino acid quantities on the blood analysis was carried out to investigate the amino acid specific characters on the blood in four type of physical constitution 1. In TAE-EUM-IN group, compared with control group, the proline and the serine were more observed. 2. In SO-EUM-IN group, compared with control group, the aspartic acid was more observed. 3. In SO-YANG-IN group, compared with control group, the proline was more observed. but the threonine and the aspartic acid were less observed. 4. In SO-EUM-IN group, compared with TAE-EUM-IN group, the aspartic acid and the serine were more observed. 5. In SO-YANG-IN group, compared with TAE-EUM-IN group, the serine and the proline were more observed, but the glutamic acid and the threonine were less observed. 6. In SO-YANG-IN group, compared with SO-EUM-IN group, the threonine and the aspartic acid were less observed.

• Biomedical Science Letters
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• v.10 no.4
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• pp.347-351
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• 2004

Maggot fibrolase (MsMg-1) was purified from the maggots of Mimela splendems using ammonium sulfate fractionation, DEAE Affi-gel affinity chromatography. This protease had a molecular weight of 85 kDa as determined by SDS-polyacrylarnide gel electrophoresis under reducing conditions. It showed strong proteolytic and fibrinolytic activities. The purified enzyme was strongly inhibited by phenylmethanesulfonyl fluoride, Mn/sup 2+/, and Zn/sup 2+/ but it was not by EDTA, EGT, Mg/sup 2+/, Ca/sup 2+/, and Li/sup 2+/ ions. In these experimental results, we have speculated that MsMg-1 is a serine protease with a strong fibrinolytic activity.

• BMB Reports
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• v.36 no.4
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• pp.421-425
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• 2003

The serine/threonine protein kinase family is a large and diverse group of enzymes that are involved in the regulation of multiple cellular pathways. Elevated kinase activity has been implicated in many diseases and frequently targeted for the development of pharmacological inhibitors. Therefore, non-radioactive antibody-based kinase assays that allow high throughput screening of compound libraries have been developed. However, they require a generation of antibodies against the phosphorylated form of a specific substrate. We report here a time-resolved fluorescence assay platform that utilizes a commercially-available generic anti-phosphothreonine antibody and permits assaying kinases that are able to phosporylate threonin residues on protein substrates. Using this approach, we developed an assay for Cdc7/Dbf4 kinase activity, determined the $K_m$ for ATP, and identified rottlerin as a non-ATP competitive inhibitor of this enzyme.

• Mycobiology
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• v.31 no.4
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• pp.209-213
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• 2003

Aspergillus flavus K-03 isolated from poultry forming soil in Korea was studied for its ability to produce extracellular proteases on basal medium containing 2%(w/v) chicken feathers. The fungus was observed to be a potent producer of such enzymes. Keratinolytic enzyme secretion was the best at 15 days of incubation period at pH 9 and temperature $40^{\circ}C$. No relationship existed between the enzyme yield and increase of biomass. Enzyme production was suppressed by exogenous sugars in descending order arabinose>maltose>mannose>fructose. But glucose did not influence the enzyme activity. The keratinolytic enzyme released by the fungus demonstrated the ability to decompose keratin substrates as chicken feather when exogenous glucose was present. The keratinolytic activity was inhibited by $HgCl_2$ and serine-protease inhibitors such as phenymethylsulfonyl fluoride(100%), chymostain(88%), crystalline soybean trypsin inhibtor(80%), antipain(45%) and aprotinin(40%), and was not by cystein-protease and aspartyl-protease inhibitors. The enzyme activity is only partially inhibited by metallo-protease inhibitor. Thus, the enzyme secreted by A. flavus K-03 belongs to the alkaline serine-type protease.

• Journal of Plant Biology
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• v.27 no.4
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• pp.253-261
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• 1984

Leaf discs isolated from the pea seedling grown in nutrient solution containing 5mM ammonia or nitrate exhibited a half level of photorespiration as compared with the nitrogen free control. The manifestation of the ammonia effect appeared somewhat earlier than that of nitrate effect, but this difference subsided as the culture periods was extended. The total amount of ${CO}_2$ fixed by leaves from nitrogen-supplemented seedlings showed approximately 1.5 fold increase over the control with the ammonia effect being manifested earlier than the nitrate effect. The activities of peroxisomal serine: glyoxylate aminotransferase were always higher with ammonia than nitrate, the two types of nitrogen source, however, had similar effect on conversion rate of glyoxylate into glycine. These results indicate that exogenous ammonia does not act directly as an effector of this aminotransferase in vivo. But changes in the level of the pool size of glycine and serine, both of which are the intermediates of photorespiratory process, suggest that exogenous ammonia inhibit the transformation of serine from glycine metabolically.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.96-104
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• 2019

Beauveria bassiana, one of the most common entomopathogenic fungi, has been isolated, pre defined and characterized in-house from soil of tea cultivation area. Experiments have been performed to verify the presence of chitinase as intracellular metabolite and its release as extracellular product rendering the spores with biopesticide activity. Although there are many responsible enzymes for the pest killer action of B. bassiana, binding property of chitinase depending on presence as well as absence of serine supplemented in the media has been studied with respect to the production and kinetics. A programmed investigation conclusively indicates that the isolated spore (hyphae) of B. bassiana has been metabolically enriched with the enzyme chitinase in presence of an externally added amino acid serine with its inhibitory kinetics.

• Korean Journal of Food Science and Technology
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• v.4 no.1
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• pp.36-43
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• 1972

A survey of the free amino acids and free sugars in tomato, watermelon, muskmelon, peach and plum was made by means of amino acid autoanalyzer and thin layer chromatography. The results of the survey are summarized as follows. 1) Fifteen amino acids found in fruit were aspartic acid, glutamic acid, alanine, serine, asparagine, lysine, valine, glycine, methionine, histidine, threonine, leucine, isoleucine, proline and arginine, and an unknown was found. 2) Ten kinds of amino acids were detected in tomato, peach and plum, thirteen amine acids in watermelon and muskmelon (edible part), and eleven amino acids in muskmelon (rind). 3) In general, these fruits contained similar amounts of these thirteen amino acids, and although they were not outstandingly high in any one acid they did contain a nutritionally well-balanced mixture. 4) Amino acids found in the greatest amount in fruit were following: glutamic acid and aspartic acid in tomato, asparagine and lysine in watermelon, alanine, serine and aspartic acid in musk-melon, and aspartic acid and serine in peach and plum. 5) Glucose, fructose, sucrose and maltose were detected in all fruit. The contents of glucose and fructose were high, and those of sucrose and maltose were low.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.179-184
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• 2021

Stratum corneum known as a skin barrier, which maintains water in skin, is the outer layer of the skin. Natural moisturizing factors (NMF) are one of the constituents in stratum corneum and amino acids are the highest components among NMF. In this study, we designed stearic acid-based solid lipid nanoparticles (SLNs) for improved skin penetration of serine (Ser). Ser-capsulated SLN was manufactured by double-melting emulsification method. The mean particle size and zeta potential of SLNs were 256.30 ~ 416.93 nm and -17.60 ~ -35.27 mV, respectively. The higher the degree of hydrophobicity or hydrophilicity of emulsifiers, the smaller the particle size and the higher the stability and capsulation rate. In addition, skin penetration was conducted using SkinEthic^TM RHE which is one of the reconstructed human epidermis models. The results of Ser penetration demonstrated that all SLNs enhanced than serine solution. The amount of enhanced Ser penetration from SLNs were approximately 4.1 ~ 6.2 times higher than that from Ser solution. Therefore, Ser-loaded SLN might be a promising drug delivery system for moisturizing formulation in cosmeceutical.

• Journal of Life Science
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• v.33 no.11
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• pp.859-867
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• 2023

Lupeol is a type of pentacyclic triterpene that has been reported to have therapeutic effects for treating many diseases; however, its effect on insulin resistance is unclear clear. This study examined the inhibitory effect of lupeol on the serine phosphorylation of insulin receptor substrate-1 in insulin resistance-induced 3T3-L1 adipocytes. 3T3-L1 cells were cultured and treated with tumor necrosis factor-α (TNF-α) for 24 hours to induce insulin resistance. Cells treated with different concentrations of lupeol (15 μM or 30 μM) or 100 nM of rosiglitazone were incubated. Then, lysed cells underwent western blotting. Lupeol exhibited a positive effect on the negative regulator of insulin signaling and inflammation-activated protein kinase caused by TNF-α in adipocytes. Lupeol inhibited the activation of protein tyrosine phosphatase-1B (PTP-1B)-a negative regulator of insulin signaling-and c-Jun N-terminal kinase (JNK); it was also an inhibitor of nuclear factor kappa-B kinase (IKK) and inflammation-activated protein kinases. In addition, Lupeol downregulated serine phosphorylation and upregulated tyrosine phosphorylation in insulin receptor substrate-1. Then, the downregulated phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway was activated, the translocation of glucose transporter type 4 was stimulated to the cell membrane, and intracellular glucose uptake increased in the insulin resistance-induced 3T3-L1 adipocytes. Lupeol may improve TNF-α-induced insulin resistance by downregulating the serine phosphorylation of insulin receptor substrate 1 by inhibiting negative regulators of insulin signaling and inflammation-activated protein kinases in 3T3-L1 adipocytes.