• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1059-1063
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• 2005

In the absence of organic solvent, di- and mono-acylglycerol enriched functional oil was produced by lipase-catalyzed glycerolysis in a stirred tank batch reactor. After glycerolysis for 48 hr, functional oil consisted of $47.1\%\;TAG,\;33.6\%\;DAG,\;and\;18.7\%$ MAG. In MAG and DAG, docosahexaenoic acid was found as $10.7\%\;and\;8.1\%$, respectively. During the reaction, total tocopherol content decreased, and $0.065\%$ tocopherols were existed in the functional oil produced after 48hr reaction.

• Biomedical Science Letters
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• v.14 no.2
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• pp.69-76
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• 2008

${\gamma}$-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system, and its actions are mediated by subtypes of GABA receptors named as $GABA_A$, $GABA_B,\;and\;GABA_C,\;GABA_A$, receptor consisting of ${\alpha},\;{\beta},\;{\gamma}\;and\;{\delta}$ subunits is a heterooligomeric ligand-gated chloride channel. This study was performed to investigate regulation of $GABA_A$ receptor by protein kinase C(PKC). Ion currents were recorded using gramicidine-perforated patch and whole cell patch clamp. mRNA encoding the subunits of PKC expressed in major pelvic ganglion (MPG) neurons was detected by using RT-PCR. The GABA-induced inward current was increased by PKC activators and decreased by PKC inhibitors, respectively. These effects were not associated with intracellular $Ca^{2+}$ and GAG (1-oleoyl-2-acetyl-sn-glycerol), a membrane permeable diacylglycerol (DAG) analogue. These results mean that the subfamily of PKC participating in activation of $GABA_A$ receptor would be an atypical PKC (aPKC). Among theses, ${\xi}$ isoform of aPKC was detected by RT-PCR. Taking together, we suggest that excitable $GABA_A$ receptor in sympathetic MPG neuron seemed to be regulated by aPKC, particular in ${\xi}$ isoform. The regulatory roles of PKC on excitatory $GABA_A$ receptors in sympathetic neurons of MPG may be an important factor to control the functional activity of various pelvic organs such as bowel movement, micturition and erection.

• Journal of Environmental Science International
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• v.26 no.11
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• pp.1275-1284
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• 2017

Acyltransferase (AT) catalyzes the transfer of an acyl moiety from acyl-coenzyme A (acyl-CoA) to an acceptor. ATs play important roles in the maintenance of homeostasis in the human body and have been linked to various diseases; therefore, several ATs have been proposed as potential targets for the treatment or prevention of such diseases. The AT family includes acyl-CoA:cholesterol AT (ACAT), diacylglycerol AT, and monoacylglycerol AT for the metabolism of lipids. Furthermore, recent molecular biological studies revealed the existence of their isozymes with distinct functions in the body. ACAT plays a critical role in the formation of cholesteryl esters from cholesterol and fatty acids, and is a potential target for treating hypercholesterolemia. During an experiment designed to discover biologically active compounds from herbal medicines, we isolated two known guaianolide sesquiterpene lactones from Chrysanthemum boreale Makino (Compositae). The lactones were characterized from their spectroscopic data (NMR, IR, MASS). These compounds were subjected to ACAT inhibition assay. Here, we report the isolation and structural elucidation of the compounds 8-o-acetyl-2-methoxy-10-hydroxy-3,11(13)-guaiadiene-12,6-olide and 8-acetyl-3,10-hydroxy-4(15),11(13)-guaiadiene-12,6-olide. In the ACAT inhibition assay, compound 1 showed strong inhibitory activity, with an $IC_{50}$ value $45{\mu}g/mL$, whereas compound 2 did not exhibit significant inhibitory activity with an over $100{\mu}g/mL$.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.712-719
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• 1998

Thyroid function is mainly regulated through cAMP and phophatidylinositol, and it is well known that TSH-stimulated thyroxine ($T_4$) release is inhibited by catecholamine from mouse thyroids via the ${\alpha}_1$-adrenoceptor stimulation. Previous study has established that the inhibition of $T_4$ release by ${\alpha}_1$-adrenoceptor stimulation results in activated protein kinase C (PKC). The purpose of this study was to determine if ion transport systems are involved in the inhibition of $T_4$ release elicited by ${\alpha}_1$-adrenergic agonist in mouse thyroids. TSH-, IBMX- and cAMP analogue-stimulated $T_4$ release were significantly inhibited by methoxamine, R59022 (diacylglycerol kinase inhibitor), and MDL (adenylate cyclase inhibitor). TSH-stimulated $T_4$ release could be inhibited by Bay K 8644 and cyclopiazoic acid, but not by verapamil and tetrodotoxin. The addition of nifedipine ($Ca^{2+}$ channel blocker), tetrodotoxin and lidocaine ($Na^+$ channel blockers), but not amiloride (EIPA) and ryanodine, completely blocked the inhibitory effects of methoxamine on $T_4$ release. TSH-stimulated $T_4$ release was also inhibited by benzamil ($Na^+-Ca^{2+}$ exchange inhibitor). TSH-, IBMX- and cAMP-stimulated $T_4$ release were inhibited by methoxamine or R59022, these effects were reversed by nifedipine. but not by verapamil. Furthermore, nifedipine reversed the inhibitory effects of benzamil and R59022 on TSH-stimulated $T_4$ release. These data suggest that the observed ${\alpha}_1$-adrenoceptor-mediated inhibition of $T_4$ release in mouse thyroids is the result of an increase in intracellular $Na^+$ or $Ca^{2+}$ effected via activation of fast $Na^+$ or nifedipine-sensitive $Ca^{2+}$ channels, and that $Na^+-Ca^{2+}$ exchange may play an important role in reducing thyroid hormone by increasing intracellular $Ca^{2+}$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1052-1058
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• 2005

Structured lipid (SL) was synthesized by enzymatic interesterification with algae oil containing docosahexaenoic acid (DHA) and soybean oil in the stirred-batch type reactor. The reaction was performed for 15hr at $65^{\circ}C$ with 300 rpm catalyzed by sn-1,3 specific Lipozyme RM 1M lipase from Rhizomucor miehei ($11\%$ by weight of total substrates) in the absent organic solvent. SL contained $87.1\;area\%$ triacylglycerol (TAG), $12.1\;area\%$ diacylglycerol (DAG), $0.6\;area\%$ monoacylglycerol (MAG), and $0.2\;area\%$ free fatty acid (FFA). Major fatty acid profiles of SL were DHA $(15.7\;mol\%)$, linoleic $(31.1\;mol\%)$, palmitic $(20.2\;mol\%)$, oleic $(13.5\;mol\%)$ and eicosapentaenoic acid $(EPA,\;6.6 mol\%)$. SL contained the newly synthesized several peaks. Iodine and saponification of SL were 206.7 and 183.8. SL color showed darker and redder than soybean oil, and appeared the most yellowish color among SL, soybean, and algae oil.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.7
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• pp.943-954
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• 2009

Diacylglycerol acyltransferase (DGAT) is a key enzyme that catalyzes the final and rate-limiting step of triglyceride synthesis. Both DGAT1 and DGAT2 genes code proteins with DGAT activity. Studies have shown DGAT1 polymorphisms associate with intramuscular fat deposition in beef cattle, but fewer associations between DGAT2 and beef cattle economic traits have been reported. The objective of this study was to investigate single nucleotide polymorphism (SNP) in intron3 of bovine DGAT2 and evaluate the associations of that with carcass, meat quality, and fat yield traits. Test animals were 157 commercial feedlot steers belonging to 3 Chinese native breeds (22 for Luxi, 24 for Jinnan, and 23 for Qinchuan), 3 cross populations (20 for Charolais${\times}$Fuzhou, 18 for Limousin ${\times}$Luxi, and 17 for Simmental${\times}$Jinan) and 1 Taurus pure breed population (16 Angus steers). In the current study, 15 SNP were discovered in intron3 and exon4 of DGAT2 at positions 65, 128, 178, 210, 241, 255, 270, 312, 328, 334, 365, 366, 371, 415, and 437 (named as their positions in PCR amplified fragments). Only 7 of them (128, 178, 241, 270, 312, 328, and 371) were analyzed, because SNP in three groups (65-128-255, 178-210-365 and 241-334-366) were in complete linkage disequilibrium within the group, and SNP 415 was a deletion and 437 was a null mutation. Frequencies for rare alleles in the 3 native breed populations were higher than in the 3 cross populations for 178 (p = 0.04), 270 (p = 0.001), 312 (p = 0.03) and 371 (p = 0.002). A general linear model was used to evaluate the associations between either SNP genotypes or allele substitutions and the measured traits. Results showed that SNP 270 had a significant association with the fat yield associated with kidney, pelvic cavity, heart, intestine, and stomach (KPHISY). Animals with genotype CC and CT for 270 had less (CC: -7.71${\pm}$3.3 kg and CT: -5.34${\pm}$2.5 kg) KPHISY than animals with genotype TT (p = 0.02). Allele C for 270 was associated with an increase of -4.26${\pm}$1.52 kg KPHISY (p = 0.006) and $-0.92{\pm}0.45%$ of retail cuts weight percentage (NMP, Retail cuts weight/slaughter body weight) (p = 0.045); allele G for 312 was associated with an increase of -5.45${\pm}$2.41 kg KPHISY (p = 0.026). An initial conclusion was that associations do exist between DGAT2 gene and carcass fat traits. Because of the small sample size of this study, it is proposed that further effort is required to validate these findings in larger populations.

• Journal of Life Science
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• v.30 no.9
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• pp.826-833
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• 2020

Phospholipase C gamma (PLCγ) has critical roles in receptor tyrosine kinase- and non-receptor tyrosine kinase-mediated cellular signaling relating to the hydrolysis of phosphatidylinositol 4,5-bisphosphate [PI(4,5)P₂] to produce inositol 1,4,5 trisphosphate (IP₃) and diacylglycerol (DAG), which promote protein kinase C (PKC) and Ca²⁺ signaling to their downstream cellular targets. PLCγ has two isozymes called PLCγ1 and PLCγ2, which control cell growth and differentiation. In addition to catalytically active X- and Y-domains, both isotypes contain two Src homology 2 (SH2) domains and an SH3 domain for protein-protein interaction when the cells are activated by ligand stimulation. PLCγ also contains two pleckstrin homology (PH) domains for membrane-associated phosphoinositide binding and protein-protein interactions. While PLCγ1 is widely expressed and appears to regulate intracellular signaling in many tissues, PLCγ2 expression is restricted to cells of hematopoietic systems and seems to play a role in the regulation of immune response. A distinct mechanism for PLCγ activation is linked to an increase in phosphorylation of specific tyrosine residue, Y783. Recent studies have demonstrated that PLCγ mutations are closely related to cancer, immune disease, and brain disorders. Our review focused on the physiological roles of PLCγ by means of its structure and enzyme activity and the pathological functions of PLCγ via mutational analysis obtained from various human diseases and PLCγ knockout mice.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.797-802
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• 2003

Structured lipids (SL) were synthesized by esterification of corn oil and conjugated linoleic acid (CLA) in a continuous packed-bed column reactor. The effects of flow rate, reaction temperature, and substrate molar ratios were studied. The reaction was catalyzed by TL IM (immobilized lipase from Thermomyces lanuginosa). Results of triacylglycerol (TAG) analysis by GC showed that the incorporated CLA isomers were mainly cis9, trans11- and trans 10, cis12-CLA. Slower flow rates yielded higher incorporation, and maximum incorporation of CLA was obtained with a molar ratio of 1:3 (corn oil: CLA) at a temperature of $55^{\circ}C$. The obtained SLs had iodine values ranging from 120 to 128. The SLs were composed of TAG $(98{\sim}99%)$, 1,2- and 1,3-diacylglycerol ($0.7{\sim}1.3%$), and a small amount of monoacylglycerol.

• BMB Reports
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• v.41 no.6
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• pp.415-434
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• 2008

Phosphoinositide-specific phospholipase C is an effector molecule in the signal transduction process. It generates two second messengers, inositol-1,4,5-trisphosphate and diacylglycerol from phosphatidylinositol 4,5-bisphosphate. Currently, thirteen mammal PLC isozymes have been identified, and they are divided into six groups: PLC-$\beta$, -$\gamma$, -$\delta$, -$\varepsilon$, -$\zeta$ and -$\eta$. Sequence analysis studies demonstrated that each isozyme has more than one alternative splicing variant. PLC isozymes contain the X and Y domains that are responsible for catalytic activity. Several other domains including the PH domain, the C2 domain and EF hand motifs are involved in various biological functions of PLC isozymes as signaling proteins. The distribution of PLC isozymes is tissue and organ specific. Recent studies on isolated cells and knockout mice depleted of PLC isozymes have revealed their distinct phenotypes. Given the specificity in distribution and cellular localization, it is clear that each PLC isozyme bears a unique function in the modulation of physiological responses. In this review, we discuss the structural organization, enzymatic properties and molecular diversity of PLC splicing variants and study functional and physiological roles of each isozyme.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.186-186
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• 1994

Many agonists have been known to activate the hydrolysis of membrane phospholipids through the bindings with corresponding receptors on the various cells. Diacylglycerol and inositol 1,4,5-trisphosphate(IP3) generated by the action of phosphoinositide-specific phospholipase C (PI-PLC) are well known second messengers for the activation of protein kinase C and the mobilization of Ca2+ in many cells. Three types of PI-PLC isozyme (${\alpha}$,${\gamma}$, and $\delta$) and several subtrpes for each type have been identified from mammalian sources by purification of enzymes and cloning of their cDNAs. Each type PI-PLC isozyme is coupled to different receptors and mediators, for example, ${\beta}$-types are coupled to the seven-transmembrane-receptors via Gq family of G-proteins and ${\beta}$-types directly to the receptor tyrosine kinases. Specific modulators for the signaling pathway through each type of PI-PLC should be very useful as potential potential candidates for lend substances in developing novel drugs. To establish the sensitive and convenient screening systems for searching modulators on PI-PLC mediated signaling, two kinds of approaches have been tried. (1) Establishment of in vitro assay condition for each type of PI-PLC isozyme: Overexpression by using vaccinia virus and purification of each isozyme was carried out for the preparation of large amounts of enaymes. Optimum and sensitive assay condition for the measurements of PI-ELC activities were established. (2) Development of the cell lines in which each type of PI-PLC is permanently overexpressed: A fibroblast cell line (3T3${\gamma}$1-7) in which PI-PLC-${\gamma}$1 was overexpressed by using pZip-neo expression vector was developed and used for the measurement of PDGF-induced IP3 formation. The responses for IP3 formed in 3T3${\gamma}$1-7 cells by the treatment of PDGF is 8 times more sensitive than those in control cells. 3T3${\gamma}$l-7 cell is useful for the screening of the inhibitors on the PDGF-induced cellular responses from large number of samples in a small volume(50 ${\mu}$l) and short time(5-15 min). Using these systems, we screened hundreds of herb-extracts for the inhibition of PDGF-induced IP3 formation and selected several extracts that showed the inhibition as the candidates for isolation and characterization of active substances. The determination of the acting point of selected extracts or fractions in the PDGF signaling pathway has been analyzing.