• Reproductive and Developmental Biology
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• 제34권1호
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• pp.7-13
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• 2010

The binding affinity constants ($p(Od)_{50}$) and molecular docking scores (OS) between porcine odorant binding proteins pOBP (1HQP) and pPBP (1GM6) as receptor and a series of tetrahydrofuran-2-yl (A & B) analogues as substrate, and their interactions were discussed quantitatively using three-dimensional quantitative structure-activity relationship (30-QSAR) models. The statistical qualities of the optimized CoMF A models for pOBP were better than those of the CoMSIA models. The binding affinity constants and OS between substrate and receptor molecules were dependent upon steric and hydrophobic interaction. The DS constants of the substrates into the binding site of OBP (1HQP) were bigger than those of PBP (1GM6). The resulting contour maps produced by the optimized CoMFA model were used to identify the structural features relevant to the binding affinity in binding site of pOBP.

• Asian Pacific Journal of Cancer Prevention
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• 제15권23호
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• pp.10137-10142
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• 2015

Apoptosis is a general phenomenon of all multicellular organisms and caspases form a group of important proteins central to suicide of cells. Pathologies like cancer, Myocardial infarction, Stroke, Sepsis, Alzheimer's, Psoriasis, Parkinson and Huntington diseases are often associated with change in caspase 3 mediated apoptosis and therefore, caspases may serve as potential inhibitory targets for drug development. In the present study, two series of synthetic acetylated tetrapeptides containing aldehyde and fluromethyl keto groups respectively at the C terminus were proposed. All these compounds were evaluated for binding affinity against caspase 3 structure. In series 1 compound Ac-DEHD-CHO demonstrated appreciable and high binding affinity (Rerank Score: -138.899) against caspase 3. While in series 2 it was Ac-WEVD-FMK which showed higher binding affinity (Rerank Score: -139.317). Further these two compounds met ADMET properties and demonstrated to be non-toxic.

• 한국미생물·생명공학회지
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• 제27권4호
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• pp.298-303
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• 1999

An $\alpha$-D-galactosidase ($\alpha$-D-galactoside galactohydrolase, EC 3. 2. 1. 22) from earthworm was purified by affinity chromatography using N-$\varepsilon$-aminocaproyl-$\alpha$-D-galactopyranosylamine coupled to sepharose and its properties were examined. The specific activity of the purified enzyme, tested with p-nitrophenyl-$\alpha$-D-galactopyranoside as substrate, was 314 units/mg protein, representing an 122-fold purification of the original crude extract. The final preparation obtained from by Sephadex G-25 chromatography showed a single band on SDS-polyacrylamide gel electrophoresis. The molecular weight was determined to be 48,000 by SDS-polyacrylamide gel electrophoresis. The purified galactosidase was showed maximum activity at pH 4.5 and 4$0^{\circ}C$, and was stable in the pH and temperature ranges from 4.0 to 5.5 and 30 to 5$0^{\circ}C$, respectively. The enzyme activity was inhibited by Zn2+, Hg2+ and Co2+. When the purified $\alpha$-galactosidase treated to guar gum for 6 hour, gel-promoting property was increased. It was clear that enzymatic elimination of galactose from guar gum by purified $\alpha$-galactosidase would lead to a significant increase in gelation ability.

• Archives of Pharmacal Research
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• 제20권4호
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• pp.351-357
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• 1997

A series of 4-substituted-kynurenic acid derivatives possessing several different substituents at C4-position which are consisted of both a flexible propyloxy chain and an adjunct several type of carbonyl groups has been synthesized and evaluated for their in vitro antagonist activity at the glycine site on the NMDA receptor. Of them, N-benzoylthiourea 15c and N-phenylthiourea 15a were found to have the best in vitro binding affinity with $IC_{50}$ of 3.95 and $6.04{\mu}M$, respectively. On the other hand, in compounds 12a-c and 13 the displacement of a thiourea group to an amide or a carbamate caused a significant decrease of the in vitro binding affinity. In the SAR study of the 4-substituted kynurenic acid derivatives, it was realized that the terminal substitution pattern on a flexible C4-propyloxy chain of kynurenic acid nucleus significantly influences on the binding affinity for glycine site; the binding affinity to the NMDA receptor might be increased by the introduction of a suitable electron rich substituent at C4 of kynurenic acid nucleus.

• Asian Pacific Journal of Cancer Prevention
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• 제17권3호
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• pp.1571-1576
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• 2016

Alteration of the acetylation status of chromatin and other non-histone proteins by HDAC inhibitors has evolved as an excellent epigenetic strategy in treatment of cancers. The present study was sought to identify compounds with positive pharmacological profiles targeting HDAC1. Analogues of Vorinostat synthesized by Cai et al, 2015 formed the test compounds for the present pharmacological evaluation. Hydroxamte analogue 6H showed superior pharmacological profile in comparison to all the compounds in the analogue dataset owing to its better electrostatic interactions and hydrogen bonding patterns. In order to identify compounds with even better high affinity and pharmacological profile than 6H and Vorinostat, virtual screening was performed. A total of 83 compounds similar to Vorinostat and 154 compounds akin to analogue 6H were retrieved. SCHEMBL15675695 (PubCid: 15739209) and AKOS019005527 (PubCid: 80442147) similar to Vorinostat and 6H, were the best docked compounds among the virtually screened compounds. However, in spite of having good affinity, none of the virtually screened compounds had better affinity than that of 6H. In addition SCHEMBL15675695 was predicted to be a carcinogen while AKOS019005527 is Ames toxic. From, our extensive analysis involving binding affinity analysis, ADMET properties predictions and pharmacophoric mappings, we report Vorinostat hydroxamate analogue 6H to be a potential candidate for HDAC inhibition in treatment of cancers through an epigenetic strategy.

• 멤브레인
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• 제18권3호
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• pp.214-218
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• 2008

전기방사를 이용하여 polyethersulfone (PES)-bovin albumin serum (BSA) 단백질 친화막을 제조하였으며, 이때 전기방사에 의한 공정상의 문제점을 용해도가 높고, 끓는점이 높은 2,2,3,4,4,4-Hexafluoro-1-butanol (HFB)를 공용매로 사용함으로써 해결하였다. 또한 공용매는 최적의 온도, 습도 범위를 확대시켜줌으로써 친화막의 대량 생산이 용이하리라 생각한다. 제조된 친화막은 biuret test를 통하여 친화막의 색깔이 무색에서 보라색으로 변함으로써 PES 섬유 내 BSA가 존재함을 확인할 수 있었다. 완충용액의 조성 성분 중 dimethyl sulfoxide (DMSO)는 세척과정에서 BSA와 L-tryptophan사이의 해리를 제어함으로써 용출과정에서 비교실험보다 약 5배의 높은 용출량을 보여주었다.

• Applied Biological Chemistry
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• 제50권2호
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• pp.107-110
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• 2007

일반적 대장균 배지 조건에서는 발현되지 않는 대장균 K-12의 laccase gene(yacK)을 PCR로 증폭한 후 pET28c에 클로닝하여 과량 발현시켰다. 과량 생산된 laccase를 His-affinity 칼럼 크로마토그래피로 정제하였다. SDS-PAGE 방법으로 확인한 과량 발현된 단백질의 분자량은 약 55,000이었으며, guaiacol 용액과 agar 배지에서 역가를 보여주었고 최적 온도는 65$^{\circ}C$, 최적 pH는 5이었다.

• BMB Reports
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• 제47권3호
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• pp.130-134
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• 2014

The combination of a high-affinity antibody to a hapten, and hapten-conjugated compounds, can provide an alternative to the direct chemical cross-linking of the antibody and compounds. An optimal hapten for in vitro use is one that is absent in biological systems. For in vivo applications, additional characteristics such as pharmacological safety and physiological inertness would be beneficial. Additionally, methods for cross-linking the hapten to various chemical compounds should be available. Cotinine, a major metabolite of nicotine, is considered advantageous in these aspects. A high-affinity anti-cotinine recombinant antibody has recently become available, and can be converted into various formats, including a bispecific antibody. The bispecific anti-cotinine antibody was successfully applied to immunoblot, enzyme immunoassay, immunoaffinity purification, and pre-targeted in vivo radioimmunoimaging. The anti-cotinine IgG molecule could be complexed with aptamers to form a novel affinity unit, and extended the in vivo half-life of aptamers, opening up the possibility of applying the same strategy to therapeutic peptides and chemical compounds.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.52-55
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• 2000

Structually organized mono- and multilayers were developed on gold for the catalytic and affinity biosensing using hyper-branched dendrimers. For the catalytic biosensing interface, a new approach to construct a multilayered enzyme film on the electrode surface was developed. The film was prepared by layer-by-layer depositions of dendrimers and periodate-oxidized glucose oxidase. The voltammograms obtained from the GOx/dendrimer multilayered electrodes revealed that bioelectrocatalytic response is directly correlated to the number of deposited bilayers. From the analysis of voltammetric and ellipsometric signals, the coverage of active enzyme per layer during the layering steps was estimated, demonstrating the spatially-ordered multilayer formation. As an extension of the study, dendrimers having various degrees of ferrocenyl modification were prepared and used. The resulting electrodes were electrochemically characterized, and the density of ferrocenyl groups, active enzyme coverage, and sensitivity were estimated. For the affinity-sensing surrface, a biosensor system based on avidin-biotin interaction was developed. As the building block of affinity monolayer, G4 dendrimer having partial ferrocenyl-tethered surface groups was prepared and used. And the biotinylated and electroactive dendritic monolayer was used for the affinity-sensing surface interacting with avidin. Electrochemical characterization of the resulting biosensor was conducted using free enzyme in electrolyte in terms of degree of surface coverage with avidin and subsequent surface shielding.

• 한국압력기기공학회 논문집
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• 제8권3호
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• pp.23-27
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• 2012

A seawater pumps in the nuclear power plant is responsible for providing cooling water to other components all the time. Because of the depreciation, the seawater pump with current impeller consumes too much power for maintaining the total head. Therefore the objective of this study is to reduce power with maintaining certain the total head by cutting the current impeller. By using a commercial CFD code, FLUENT, the overall performance of seawater pump with current and modified impeller was simulated. Also Affinity law was applied at pumps with various impeller diameter and evaluated the validity of the affinity law. The numerical results show that the pump efficiency is quite irrelevant to the diameters of the impellers and the pump efficiency becomes worse over the designed flow rate. And affinity law result and numerical one show good agreements at small change of impeller diameter. One of the impeller diameters was decided to modify and was applied to the nuclear power plant with the numerical study above.