• 한국전자현미경학회:학술대회논문집
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• 1997.11a
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• pp.53-53
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• 1997

• The Journal of Natural Sciences
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• v.14 no.2
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• pp.83-91
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• 2004

Recently phage K11 lysozyme was cloned and characterized in our lab. The K11 lysozyme was identified to have dual functions. It not only cuts a peptidoglycan bond in bacterial cell wall but also acts as an inhibitor of K11 RNA polymerase. It has been known that the T7 lysozyme binds specifically to T7 RNA polymerase and inhibits transcription. The dual activities of K11 lysozyme are atreeable to the case of T7 phage lysozyme and RNA polymerare. In order to identify the binding magnitude of K11 lysozyme with K11 RNA polymerase, yeast two-hybrid system was used. K11 phage lysozyme gene was introduced into pLexA plasmid and used as a prey. Also, K11 phage RNA polymerase gene was introduced into pJG4-5 and used as a bait. The binding between K11 lysozyme and K11 RNA polymerase was demonstrated by expression of reporter genes such as lacZ and leu2.

• Journal of Life Science
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• v.28 no.3
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• pp.307-313
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• 2018

Alopecia cause psychological stress due to their effect on appearance. Thus, the global market size of the alopecia treatment products are growing quickly. Timosaponin A III is the well known active ingredient of Anemarrhenae Rhizoma. In this study, we investigated and compared the binding affinity of timosaponin A III with finasteride (5-beta reductase antagonist) and minoxidil (androgen receptor antagonist) on the target protein active site by in silico computational docking studies. The three dimensional crystallographic structure of 5-beta reductase (PDB ID : 3G1R) and androgen receptor (PDB ID: 4K7A) was obtained from PDB database. In silico computational autodocking analysis was performed using PyRx, Autodock Vina, Discovery Studio Version 4.5, and NX-QuickPharm option based on scoring functions. The timosaponin A III showed optimum binding affinity (docking energy) with 5-beta reductase as -12.20 kcal/mol as compared to the finasteride (-11.70 kcal/mol) and with androgen receptor as -9.00 kcal/mol as compared to the minoxidil (-7.40 kcal/mol). The centroid X, Y, Z grid position of the timosaponin A III on the 5-beta reductase was similar (overlap) to the finasteride, but the X, Y, Z centroid grid of the timosaponin A III on the androgen receptor was significantly far from the minoxidil centroid position. These results significantly indicated that timosaponin A III could be more potent antagonist to the 5-beta reductase and androgen receptor. Therefore, the extract of Anemarrhenae Rhizoma or timosaponin A III containing biomaterials can substitute the finasteride and minoxidil and can be applied to the alopecia protecting product and related industrial fields.

• Journal of fish pathology
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• v.14 no.1
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• pp.31-36
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• 2001

A novel clonidine binding sites were characterized in the intestinal membrane isolated from seawater eels, Anguilla japonica. The specific clonidine binding sites consisted of at least two classes, high affinity ($K_d=1.4{\pm}0.3$ nM n = 5) and low affinity ($K_d=175{\pm}34$ nM n = 5) sites. The specific binding of 2 nM [$^3H$]clonidine was most enhanced at $20^{\circ}C$ and pH 7.5, and reversed by unlabelled clonidine. Such binding was hardly inhibited by adrenaline, yohimbine or rauwolscine, indicating that most binding sites are distinct from $\alpha_2$-adrenoceptor. The specific clonidine binding sites was inhibited by various imidazoline/guanidinium drugs, indicating existence of imidazoline/guanidinium receptive sites (IGRS) or imidazoline receptors in the eel intestine. Competition experiments revealed that rank order to displace 2 nM [$^3H$]clonidine from their binding sites was as follows : guanabenz > cirazoline = naphazoline = UK14,304 = ST587 $\geq$ clonidine $\geq$ idazoxan = RX821002 = tolazoline > ST93 = oxymetazoline = amiloride = ST91 > yohimbine = efaroxan = rauwolscine $\geq$ adrenaline = ST567 = histamine = agmatine. Although physiological role of IGRS is not clear yet even in mammalian cell/tissues, eel intestine may be a good model to elucidate how the IGRS act in the cell and to decide what is the endogenous ligand for the IGRS.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.239-242
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• 2012

효모 (Saccharomyces Cervisiae)는 단일 세포의 형태로 존재하는 진핵 세포로써 동물세포와 유사한 기작으로 분비성 단백질을 생성한다. 따라서 박테리아와 달리 효모를 이용하면 당단백질이나 이황결합을 포함하는 분비성 단백질을 경제적으로 대량 합성할 수 있다. 효모의 필수 단백질 중 하나인 단백질 이황이성질화 효소는 소포체에 위치하며 분비성 단백질에 구조적으로 안정한 이황결합을 제공하는 효소이다. 본 연구는 단백질 이황이성질화 효소 (protein disulfide isomerase)가 지니고 있는 두 개의 활성도메인 중 분비성 단백질들의 합성 효율에 직접적으로 관여하는 부위를 찾는 연구이다. 효모 유전체로부터 단백질 이황이성질화 효소의 유전자 (PDI1)을 제거하고 효소의 변이 유전자를 주입한 후 효모의 성장 속도를 측정하였다. 또한 효모의 대표적 분비성 단백질을 각 변이 효소를 지니는 효모에 과발현시켜 합성 및 이황결합 형성 효율을 측정하였다. 단백질 이황이성질화 효소내 두 개의 활성 부위 중 아미노 말단쪽에 위치한 a 도메인에 있는 활성 부위가 분비성 단백질의 활성에 중요한 역할을 한다는 것을 알 수 있었다. 이 결과는 이황결합이나 당을 포함하는 외래 단백질의 고효율 합성을 위한 새로운 효모종 개발에 중요한 정보를 제공할 것으로 기대 된다.

• The Korean Journal of Zoology
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• v.38 no.4
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• pp.523-530
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• 1995

Specific affinity binding sites for atrial natriuretic peptide (ANP) were Investigated in the pig ovarian tissues by in vitro autoradiographic techniques. In the pig ovary, the highest binding sites for 12514abeiled rANP(l~28) were localized in the granulosa cell layer of the forncles. The binding sies on theca layer of the ovarian follicles were mainly localized in the external layer, but none was observed In the Internal layer. In the corpus luteum, the binding site was not observed. The specific bindings of 200 pM of l2Sl4abelled rANP(l~28) to granulosa and theca externa layers were reversed completely by excess concentration (1 ~4) of unlabelled rANP(l~28) but not by 10 ~ of unrelated peptides, human angiotensin II and arginine vasopressin. The binding was also displaced by 1 ~ of desiGIn18, Ser19, Gly2O, leu21, Gly22I ANP(4~2g) (C- ANF) as a spedfic ligand of the ANP clearance receptor. Therefore these results indicate ~hat the biological and the clearance ANP receptors exist in the theca externa and granulosa layer of the pig ovary, and suggest that the ANP receptors may be related with the regulatory lundion of the ovarian follicular development including oocyte maturation.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.45-45
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• 1992

Calcium channel에 작용하는 dihydropyridine(DHP) 계열의 calcium channel 효능제와 길항제의 caicium channel에 대한 작용과 muscarinic receptor에 대한 작용과의 관계를 조사하기 위하여 [$^3$H]QNB와 [$^3$H]nitrendipine 결합실험을 시행하고 이를 지표로 하여 칼슘효능제와 길항제의 이들 receptors에 대한 결합성질을 검토하였다. 본 연구결과 칼슘 channel 효능제인 Bay K 8644는 칼슘길항제인 nicardipine 및 nimodipine과 같이 고농도에서 muscarinic receptor에 대한 [$^3$H]QNB결합을 경쟁적으로 억제하였으며 이들 약물의 muscarinic receptor에 대한 Ki치는 각각 16.7 $\mu$M, 3.5 $\mu$M, 및 15.5 $\mu$M이었다. 한편, 이들 약물은 다같이 칼슘 channel의 high affinity DHP결합부위에 대한 [$^3$H]nitrendipine 결합을 억제하였으나 이 부위에 대한 Bay K 8644, nicardipine, 및 nimodipine의 Ki치는 각각 4 nM, 0.1 nM, 및 0.2 nM로서 muscarinic receptor에 대한 Ki치 보다 4,000-75,000배 작았다. 뿐만 아니라 [$^3$H]QNB결합을 완전히 차단하는 고농도의 atropine(1 $\mu$M)에 의해서도 [$^3$H]nitrendipine결합이 전혀 영향을 받지 않았다. 따라서 DHP계 약물의 muscarinic receptor에 대한 작용은 칼슘channel에 대한 이들 약물의 작용을 연구하거나 임상적 치료 목적으로 사용할때는 나타나지 않을 것으로 생각된다.

• Restorative Dentistry and Endodontics
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• v.28 no.4
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• pp.314-325
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• 2003

이 연구의 목적은 수종 상아질 접착 시스템과 복합 레진 및 resin-modified glass ionomer를 상아질 표면에 접착하여 재료 및 상아질내 위치에 따른 미세전단결합강도를 측정, 비교하는 것이다. 상아질 접착 시스템으로는, 3-step인 Scotchbond Multi-Purpose Plus, 2-step인 Single Bond와 자가 부식형 시스템인 Clearfil SE Bond를, 1-step인 Prompt L-Pop을 사용하였다. 이와 함께 hybrid type의 복합 레진인 Clearfil AP-X와 2250을 사용하였으며 resin-modified glass ionomer로는 Fuji II LC를 사용하였다. 상악 소구치를 치아의 근원심 중앙부를 절단하여 상아질면을 노출시켰다. 5개 실험군으로 분류하고 상아질면을 위치에 따라 치관부의 occlusal $\frac{1}{3}$, middle $\frac{1}{3}$, cervical $\frac{1}{3}$과 치근부로 구분지어 시편을 부착하였다. 미세전단결합강도측정는 Universal testing machine(EZ-test; Shimadzu, Japan)에서 측정하였다. Occlusal 1/3부위에서는 SE가 가장 높은 값을, SM과 SB간에는 유의차가 없었으며, PL, GI순으로, Middle 1/3부위에서는 $SM{\;}{\geq}{\;}SE{\;}{\geq}{\;}SB{\;}{\geq}{\;}PL{\;}{\geq}{\;}GI$순으로, cervical 1/3부위에서는 SM, SE, SB간에 유의차가 없었다. Root dentin에서는 SM이 가장 높은 값을 보였으며 SE, PL, GI간에 유의차가 없었다. SE만이 치관부 상아질에 비해 치근부에서 유의할만한 결합강도의 감소를 나타냈다(p<0.05). GI는 치관부 상아질에서는 다른 군에 비해 유의성 있게 낮은 결합강도를 보였으나 치근부에서는 SE, PL과 유의차가 없었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5350-5355
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• 2012

Human tyrosinase (hTyr) catalyzes the first and rate limiting step in the biosynthesis of a skin color determinant, melanin. Although a number of cosmetic companies have tried to develop hTyr inhibitors for several decades, absence of 3D structure of hTyr make it impossible to design or screen inhibitors by structure-based approach. Therefore, we built a 3D structure by comparative modeling technique based on the crystal structure of tyrosinase from Bacillus megaterium to provide structural information and to search new hit compounds from database. Our model revealed that two copper atoms of active site located deep inside and were coordinated with six strictly conserved histidine residues coming from four-helix-bundle. Substrate binding site had narrow funnel like shape and its entrance was wide and exposed to solvent. In addition, hTyr-tyrosine and hTyr-kojic acid, a well-known inhibitor, complexes were modeled with the guide of solvent accessible surface generated by in-house software. Our model demonstrated that only phenol group or its analogs could fill the binding site near the nuclear copper center, because inside of binding site had narrow shape relatively. In conclusion, the results of this study may provide helpful information for designing and screening new anti-melanogenic agents.

• Journal of Life Science
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• v.26 no.2
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• pp.253-258
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• 2016

In this study, nano-micelled curcumin was produced with natural sea salt with a view to comparing the in silico molecular binding affinity of pure curcumin compound to the active site of transthyretin. Using an optical light microscope and an electron microscope, it was found that the structure of the surface and the cross-section of nano-micelled curcumin was significantly different from natural sea salt. In particular, the crystal structure and nano-components in the nano-micelled curcumin were united, and the layer was more strongly stabilized than untreated salts. In the virtual 3D structure, in silico molecular docking study, the ligand binding affinity of nano-micelled curcumin to the transthyretin active site was found to be higher than that of pure curcumin. In addition, a nano-micelled curcumin formula interacted with more amino acid residues of transthyretin domains. The pharmacophore feature of the nano-micelled curcumin also showed more condensed and constrained features than normal curcumin. These results suggest that nano-micelled curcumin may effectively bind to and stabilize transthyretin, thereby regulating transthyretin-related physiological diseases. Collectively, the nano-micelled curcumin process suggests that normal curcumin can be modified more efficiently into the novel bio-functional chemical formula to stabilize the transthyretin structure. Therefore, the nano-micelled curcumin process can be applied to the field of the regulation of Alzheimer's disease.