• BMB Reports
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• v.36 no.2
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• pp.149-153
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• 2003

The dibucaine number (DN) was determined for serum cholinesterase (EC 3.1.1.8, SChE) in plasma samples. The ones with a DN of 79-82 were used, because they had the "usual" SChE variant. The enzyme was assayed colorimetrically by the reaction of 5,5'-dithiobis-[2-nitrobenzoic acid] (DTNB) with the free sulfhydryl groups of thiocholine that were produced by the enzyme reaction with butrylthiocholine (BuTch) or acetylthiocholine (AcTch) substrates, and measured at 412 nm. Dibucaine, a quaternary ammonium compound, inhibited SChE to a minimum within 2 min in a reversible manner. The inhibition was very potent. It had an $IC_{50}$ of $5.3\;{\mu}M$ with BuTch or $3.8\;{\mu}M$ with AcTch. The inhibition was competitive with respect to BuTch with a $K_i$ of $1.3\;{\mu}M$ and a linear-mixed type (competitive/noncompetitive) with respect to AcTch with inhibition constants, $K_i$ and $K_I$ of 0.66 and $2.5\;{\mu}M$, respectively. Dibucaine possesses a butoxy side chain that is similar to the butryl group of BuTch and longer by an ethylene group from AcTch. This may account for the difference in inhibition behavior. It may also suggest the existence of an additional binding site, other than the anionic binding site, and of a hydrophobic nature.

• Korean Journal of Animal Reproduction
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• v.22 no.4
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• pp.331-339
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• 1998

The purpose of this study was to investigate the applicability of periodic acid thiocarbohy-drazide silver proteinate, physical development (PA-TCH-SP, -PD) stain to the seminiferous tubules for the ultrastructural studies of Sertoli cell column and Sertoli cell processes. In the Sertoli cell cloumn and Sertoli cell processes, high concentration of the reactive granules were observed under transmission electronmicroscope (TEM) after PA-TCH-SP-PD stain. Also some reactive granules were seen in the spermatogonium cytoplasm, clearly. These reactive granules specifically stained with PA-TCH-SP, -PD make the Sertoli cell column, Sertoli cell processes and spermatogonium cytoplasm easy to distinguish from nucleus of the germ cells, spermatocyte, spermatid and residual body which did not contain the reactive granules. This result indicates that the PA-TCH-SP, -PD stain is superior to other traditional electronic double stain methods for the ultrastructural studies of Sertoli cell.

• Plant Biotechnology Reports
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• v.2 no.4
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• pp.253-258
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• 2008

The cDNA of the touch-induced genes (TCH) of the sweet potato [Ipomoea batatas (L.) Lam.] has been cloned and analyzed. IbTCH1, which exists as at least two-copy genes in the genome of the sweet potato, encodes for 148-amino acid polypeptides, and harbors four conversed $Ca^{2+}-binding$ motif EF-hands. IbTCH1 was shown to be expressed in the flower, leaf, thick pigmented root, and particularly in the white fibrous root, but expressed only weakly in the petiole. IbTCH1 is upregulated upon exposure to environmental stresses, dehydration, and jasmonic acid. Furthermore, IbTCH1 is developmentally regulated in the leaf and root. These results strongly indicate that the gene performs functions in both plant development and in defense/stress-signaling pathways.

• Bulletin of the Korean Chemical Society
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• v.24 no.1
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• pp.65-69
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• 2003

The kinetic and chemical mechanisms of AChE-catalyzed hydrolysis of short-chain thiocholine esters are relatively well documented. Up to propanoylthiocholine (PrTCh) the chemical mechanism is general acid-base catalysis by the active site catalytic triad. The chemical mechanism for the enzyme-catalyzed butyrylthiocholine(BuTCh) hydrolysis shifts to a parallel mechanism in which general base catalysis by E199 of direct water attack to the carbonyl carbon of the substrate. [Selwood, T., et al. J. Am. Chem. Soc. 1993, 115, 10477- 10482] The long chain thiocholine esters such as hexanoylthiocholine (HexTCh), heptanoylthiocholine (HepTCh), and octanoylthiocholine (OcTCh) are hydrolyzed by electric eel acetylcholinesterase (AChE). The kinetic parameters are determined to show that these compounds have a lower Michaelis constant than BuTCh and the pH-rate profile showed that the mechanism is similar to that of BuTCh hydrolysis. The solvent isotope effect and proton inventory of AChE-catalyzed hydrolysis of HexTCh showed that one proton transfer is involved in the transition state of the acylation stage. The relationship between the dipole moment and the Michaelis constant of the long chain thiocholine esters showed that the dipole moment is the most important factor for the binding of a substrate to the enzyme active site.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.71-76
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• 2018

The Arabidopsis SHL1 (${\underline{Sh}}ort$ ${\underline{L}}ife$ 1) gene encodes a small nuclear protein that is critical for the proper expression of the developmental programs that are responsible for controlling plant stature, senescence, flowering and seed formation. The SHL1 contains a single PHD finger domain that works in conjunction with a bromo-adjacent homology (BAH) motif that is thought to function significantly in protein-protein interactions. The TCH4 gene of the Arabidopsis encodes a xylogluclan endotransglucosylase/hydrolase that is transcriptionally regulated by a variety of hormonal and environmental stimuli. We report here in this study that the SHL1 exhibits sequence specific DNA binding properties, recognizing a 14 bp region of the TCH4 promoter in vitro, spanning nucleotides -262 to -275 (GGAAAAAACTCCCA). Chiefly, the nuclear extracts of Arabidopsis contain a protein with similar binding properties as recombinant SHL1, which is absent in identified transgenic plants that are noted as expressing antisense SHL1 RNA. Interestingly, the SHL1 gene expression with a BL treatment in characteristically wild types of seedlings showed that the transcript level of SHL1 is significantly down regulated by the BL treatment. The SHL1 may play a subtle role in regulating the kinetics of induction of the TCH4 in response to several stimuli in vivo.

• Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.335-349
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• 2022

To optimize the hydrolysis conditions in the production of antioxidant hydrolysates from tuna cooking juice concentrate (TC) to maximize the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, TC containing 48.91% protein was hydrolyzed with Alcalase 2.4 L, and response surface methodology (RSM) was applied. The optimum hydrolysis conditions included a 2.2% (w/v) Alcalase concentration and 281 min hydrolysis time, resulting in the highest DPPH radical scavenging activity of 66.49% (0.98 µmol Trolox/mg protein). The analysis of variance for RSM showed that hydrolysis time was an important factor that significantly affected the process (p < 0.05). The effects of different drying methods (freeze drying, hot air drying, and vacuum drying) on the DPPH radical scavenging activity and amino acid (AA) profiles of TC hydrolysate (TCH) were evaluated. Vacuum-dried TCH (VD) exhibited an increase in DPPH radical scavenging activity of 81.28% (1.20 µmol Trolox/mg protein). The VD samples were further fractionated by ultrafiltration. The AA profiles and antioxidant activities in terms of the DPPH radical scavenging activity, 2,2'-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, ferric reducing antioxidant power, and ferrous ion chelating activity were investigated. Glutamic acid, glycine, arginine, and cysteine were the major AAs found in the TCH fractions. The highest DPPH radical scavenging activity was found in the VD-1 fraction (< 5 kDa). The VD-3 fraction (> 10 kDa) exhibited the highest ABTS radical scavenging activity and ferric reducing antioxidant power. The ferrous ion chelating activity was the highest in VD-1 and VD-2 (5 to 10 kDa). In conclusion, this study provided the optimal conditions to obtain high antioxidant activities through TCH production, and these conditions could provide a basis for the future application of TCH as a functional food ingredient.

• Korean Journal of Veterinary Research
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• v.36 no.3
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• pp.521-529
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• 1996

In an effort to obtain basic data of carbohydrate metabolism during spermiogenesis of the sexually-matured Jindo dog, the glycogen distribution in the testis was investigated by light and transmission electron microscopy. Periodic acid thiocarbohydrazide silver proteinate physical development(PA-TCH-SP-PD) staining method provided better results in the detection of glycogen granules from Sertoli cells and germ cells than the periodic acid schiff(PAS) staining method did. Pre-treatment of the tissue sections with ${\alpha}$-amylase elicited a significant decrease in PA-TCH-SP-PD stained granules, which suggested that the stained granules were of glycogen origin. High concentration of the glycogen granules were observed in the Sertoli cells, especially in its column, sheet-like processes, club-like processes, and tubular processes. The glycogen granules were unevenly distributed in some Sertoli cell columns. These results strongly indicated that the Sertoli cells of Jindo dogs showed vigorous activity of carbohydrate metabolism.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.4
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• pp.289-294
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• 2013

To develop a new whitening agent for cosmetics, we investigated the inhibitory effects of biochanin A on melanogenesis. The biochanoin A is an active component in the extracts of Dalbergia odorifera T. Chen. It reduced melanin contents of B16F1 melanoma cells in a dose-dependent manner and decreased to about 48% at a concentration 10 ${\mu}g/mL$. It also inhibited the expression in microphthalmia associated transcription factor (MITF), Tyrosinase, Tyrosinase related protein 1 (Trp-1), and Tyrosinase related protein 2 (Trp-2) in melanocytes. The results suggested that biochanin A has considerable potential as a cosmetics ingredient with a whitening effect.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.490-495
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• 1996

The anti-compliment activity of hemolytic complementary assay(TCH50) of rhamnan sulfate fraction obtained from water extracts of Monostroma nitidum was investigated Rhamnan sulfate Fraction, F-4-3 fraction appeared relatively strong anti-complementary activity which decreased TCH50 over 60% than that comparison with control, and F-4-3 considerably inhibited ACH50. F-4-3 inhibited formation of the classical pathway C3 convertase or C4 cleavage. The results also indicate the mode of complement activation by F-4-3 fraction shows not only the classical pathway but also the alternative pathway.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.42-50
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• 1992

We conducted screening on Chinese medicinal herbs to examine their anti-complementary activity by hemolytic complementary assay $(TCH_{50})$. Among 55 kinds of herbs, several herbs showed relatively potent anti-complementary activity which decreased $TCH_{50}$, more than 70% in comparison with control. Then, hot water extracts of the following herbs, Curcuma aromatica, Areca catechu, Gleditsiae spina, Euonymus alata, Acanthopanax senticous. Lonicera japonica, Aconitum carmichaeli, Curcuma zedoaria and Cinnamoum cassia, which were shown relatively potent anti-complementary activity were partially purified and analyzed their chemical properties. These activities were resistant to digestion with pronase but decreased by treatment with $NaIO_4$. These results may indicate that the complement activating ability in their herbs is due to polysaccharide. Furthermore, the anti-complementary activity of Areca catechu which was showed the most potent activity, was reduced partially in the absence of the $Ca^{++}\;ion$. After incubation of the normal human serum with partially purified polysaccharide of A. catechu in the absence of $Ca^{++}\;ion$, a cleavage of C3 in the serum was found to have occurred through immunoelectrophoresis using rabbit anti-human C3 serum. These results indicate that the mode of complement activation by polysaccharide of A. catechu is via both the alternative and classical pathway.