• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.2930-2936
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• 2012

A three-dimensional pharmacophore hypothesis was developed for atypical antipsychotics in order to map common structural features of highly active compounds by using HipHop in CATALYST program. The pharmacophore hypotheses were generated using 12 compounds as training set and validated using 11 compounds as test set. The most predictive hypothesis (Hypo1) comprises five features viz. two hydrophobic regions, two hydrogen bond acceptor lipid and one aromatic ring. In the absence of information like crystallized structure of 5-$HT_{2A}$ receptor and binding mode of antipsychotics with 5-$HT_{2A}$ receptor, this hypothesis will serve as a potentially valuable tool in the design of novel atypical antipsychotics acting primarily at 5-$HT_{2A}$ and $D_2$ receptors.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.236-242
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• 1986

The nucleotide sequence of the genetic control site of Bacillus subtilis gene for $(1-4)-{\beta}-D-glucan$ endoglucanase (cellulase) was determined according to the procedures of the dideoxy chain termination method(Sanger et. al., 1977). The deduced amino acid sequence of this enzyme has a hydrophobic signal peptide at the $NH_2$ terminus similar to those found in fifteen other extracellualr enzymes from Bacillus species. This is followed by a sequence resembling the Bacillus ribosome binding site 14 nucleotide before the first codon of the gene. The presumptive promoter sequence was located 92 base pairs upstream fromthe initiation codon. The homology region in signal sequences was striking when comparing all the signal sequences of sixteen extracellular enzymes from Bacillus species so far compiled.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.295-295
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• 1994

The human ${\beta}$$_2$-adrenergic receptor (h${\beta}$$_2$AR) contains seven clusters of hydrophobic amino acids suggestive of membrane-spanning domains and its gene is intronless. The genomic gene encoding h${\beta}$$_2$AR has been isolated by polymerase chain reaction. To express h${\beta}$$_2$AR in Saccharomyces cerevisiae, a modified h${\beta}$$_2$AR gene was fused to signal peptide sequence of Killer toxin gene from Kluyveromyces lactics. This fusion gene was expressed under the galactose-inducible GAL10 promoter. The ligand binding experiments showed that the functional h${\beta}$$_2$AR was expressed at a concentration three times as much as that found in Hamster lung.

• Journal of the Korean Magnetic Resonance Society
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• v.2 no.2
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• pp.131-140
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• 1998

The calcium-induced structural changes in the skeletal muscle regulatory protein troponin C (NTnC) involve a transition from a ‘closed’to an ‘open’structure with the concomitant exposure of a large hydrophobic interaction site for target proteins. Structural studies have served to define this conformational change and elucidate the mechanism of the linkage between calcium binding and the induced structural changes. There are now several structures of NTnC available from both NMR and X-ray crystallography. Comparison of the calcium bound structures reveals differences in the level of opening. We have considered the concept of a flexible open state of NTnC as a possible explanation for this apparent discrepancy. We also present simulations of the closed-to-open transition which are in agreement with the flexibility concept and with experimental energetics data.

• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1171-1174
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• 2007

We have developed an electrochemical immunosensor that combines the electrocatalytic property of carbon nanotube and the low background current of indium tin oxide (ITO) electrode. A partial monolayer of carboxylated single-walled carbon nanotube (CCNT) is covalently formed on an ITO electrode modified with amine-terminated phosphonic acid. Nonspecifically adsorbed avidin on the hydrophobic sidewalls of CCNT is used to immobilize biotinylated antibody and to reduce the nonspecific binding to CCNT. The biotinylated antimouse IgG bound on avidin and the antimouse IgG conjugated with alkaline phosphatase (ALP) sandwiches a target mouse IgG. ALP catalyzes the conversion of p-aminophenyl phosphate monohydrate into p-aminophenol, which is electrocatalytically oxidized to p-quinone imine on CCNT surface. Moderate electrocatalytic electrode obtained with the combination of CCNT and ITO allows low detection limit (0.1 ng/ mL).

• Journal of Photoscience
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• v.4 no.1
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• pp.1-5
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• 1997

A hitherto unknown diphenylbutadiene analog viz. 1-(p-N,N-dimethylaminophenyl)-4-phenyl-2-methyl-1E,3E-butadiene (10) has been prepared and its absorption, excitation, and fluorescent emission properties in different media including various organic solvents and aqueous bovine serum albumin (BSA) have been studied. For comparision, these properties have also been investigated for the parent diphenylbutadiene (2). Diene 10 exhibits solvent polarity/polarizability-sensitive fluorescence properties ($\lambda$$_{max}$, $\Phi$$_f$, $\tau$$_f$, K$_f$, f). It also binds to the hydrophobic domains of aqueous bovine serum albumin (BSA) with a binding constant of 3.89 x 10$^4$ M$^{-1}$. The relative fluorescence quantum yield of 10 increases, while, the fluorescence lifetime decreases with increasing concentration of-BSA. The results highlight the polar character of the singlet excited state of diphenylpolyenes and the utility of 10 as fluorescence probe for studying microenvironments of organized assemblies and biological supramolecular structures.

• Journal of Pharmaceutical Investigation
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• v.26 no.3
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• pp.155-168
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• 1996

The active site of cyclooxygenase was modeled by complementary receptor-cavity mapping procedure using 3D structures of the non-steroidal antiinflammatory drugs (NSAIDs). A total of 50 NSAIDs were chosen as data ligands which compete the same site on the enzyme. Partial atomic charges were estimated, and the energetic differences for various conformations were calculated so as to meet the need for a most efficient overlapping of the probably-equivalent functional groups of the ligand molecules. The structure activity relationships of the NSAIDs, if available, were fully considered throughout the modeling. The overall shape of the model obtained is similar to a boot-without-bottom. Most of inner surface of the cavity appeared as hydrophobic; two polar counterparts except the carboxyl-binding position were found. By this model, some clear explanations could be given on the experimental observations which were not satisfiably understood yet.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2003.11a
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• pp.46-46
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• 2003

Hypocholesterolemic peptide isolated from glycimin (11S protein) hydrolyzate by trypsin was purified and identified as LPYP and IAVPGEVA. To investigate the effects of phyiscal properties of side chains of the hypocholesterolemic activity, some of mutant peptides were designed and synthesized chemically. The structure related structures of each peptide were simulated and constructed and their conformations were observed by using spectropolarimeter. The hypocholesterolemic activities were monitored by assaying the inhibition of 3-hydroxy-3-methylglutaryl CoA reductase (HMG-CoA reductase) in vitro and by the determination of cholesterol content in mice serum. For LPYP derivatives, Hypocholesterolemic activity was lost when hydrophobic leucine residue at N-terminus was not so critical for maintaining hypocholesterolemic activity. For idealogical design of hypocholesterolemic peptides, the structure of HMG-CoA reductase are shown and inhibition mechanism of some peptides or inhibitors will be presented. For IAVPGEVA derivative inhibition of HMG-CoA reductase has been studied. For detail study of hypocholesterolemic activity, kinetic study of inhibition of peptides on HMG-CoA reductase and structural view of ligand binding should be investigated.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.11-11
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• 1996

The three-dimensional structure of the carboxyl-terminal domain of the E.coli RNA polymerase $\alpha$ subunit, which is regarded as the contact site for transcription activator proteins and the promoter UP element, was determined by NMR spectroscopy. Its compact structure of four helices and two long arms enclosing its hydrophobic core shows a folding topology distinct from those of other DNA-binding proteins. (omitted)

• BMB Reports
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• v.50 no.7
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• pp.367-372
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• 2017

Monoacylglycerol acyltransferase 1 (MGAT) is a microsomal enzyme that catalyzes the synthesis of diacylglycerol (DAG) and triacylglycerol (TAG). However, the subcellular localization and catalytic function domain of this enzyme is poorly understood. In this report, we identified that murine MGAT1 localizes to the endoplasmic reticulum (ER) under normal conditions, whereas MGAT1 co-localize to the lipid droplets (LD) under conditions of enriching fatty acids, contributing to TAG synthesis and LD expansion. For the enzyme activity, both the N-terminal transmembrane domain and catalytic HPHG motif are required. We also show that the transmembrane domain of MGAT1 consists of two hydrophobic regions in the N-terminus, and the consensus sequence FLXLXXXn, a putative neutral lipid-binding domain, exists in the first transmembrane domain. Finally, MGAT1 interacts with DGAT2, which serves to synergistically increase the TAG biosynthesis and LD expansion, leading to enhancement of lipid accumulation in the liver and fat.