• Journal of Ginseng Research
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• 제46권6호
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• pp.750-758
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• 2022

Background: Mild cognitive impairment (MCI) is a transitional condition between normality and dementia. Ginseng is known to have effects on attenuating cognitive deficits in neurogenerative diseases. Ginsenosides are the main bioactive component of ginseng, and their protein targets have not been fully understood. Furthermore, no thorough analysis is reported in ginsenoside-related protein targets in MCI. Methods: The candidate protein targets of ginsenosides in brain tissues were identified by drug affinity responsive target stability (DARTS) coupled with label-free liquid chromatography-mass spectrometry (LC-MS) analysis. Network pharmacology approach was used to collect the therapeutic targets for MCI. Based on the above-mentioned overlapping targets, we built up a proteineprotein interaction (PPI) network in STRING database and conducted gene ontology (GO) enrichment analysis. Finally, we assessed the effects of ginseng total saponins (GTS) and different ginsenosides on mitochondrial function by measuring the activity of the mitochondrial respiratory chain complex and performing molecular docking. Results: We screened 2526 MCI-related protein targets by databases and 349 ginsenoside-related protein targets by DARTS. On the basis of these 81 overlapping genes, enrichment analysis showed the mitochondria played an important role in GTS-mediated MCI pharmacological process. Mitochondrial function analysis showed GTS, protopanaxatriol (PPT), and Rd increased the activities of complex I in a dose-dependent manner. Molecular docking also predicted the docking pockets between PPT or Rd and mitochondrial respiratory chain complex I. Conclusion: This study indicated that ginsenosides might alleviate MCI by targeting respiratory chain complex I and regulating mitochondrial function, supporting ginseng's therapeutic application in cognitive deficits.

• Bulletin of the Korean Chemical Society
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• 제26권11호
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• pp.1695-1700
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• 2005

Catechol-O-methyltransferase (COMT, EC 2.1.1.6) is an S-adenosylmethionine (SAM, AdoMet) dependent methyltransferase, and is related to the functions of the neurotransmitters in various mental processes, such as Parkinson’s disease. COMT inhibitors represent a new class of antiparkinson drugs, when they are coadministered with levodopa. Based on x-ray structure of rat COMT (rCOMT), the three dimensional structure of human COMT (hCOMT) was constructed by comparative homology modeling using MODELLER. The catalytic site of these two proteins showed subtle differences, but these differences are important to determine the characterization of COMT inhibitor. Ligand docking study is carried out for complex of hCOMT and COMT inhibitors using AutoDock. Among fifteen inhibitors chosen from world patent, nine models were energetically favorable. The average value of heavy atomic RMSD was 1.5 $\AA$. Analysis of ligand-protein binding model implies that Arg201 on hCOMT plays important roles in the interactions with COMT inhibitors. This study may give insight to develop new ways of antiparkinson drug.

• Bulletin of the Korean Chemical Society
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• 제35권8호
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• pp.2317-2325
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• 2014

P-glycoprotein (P-gp) is a member of the ATP-Binding Cassette transporter superfamily and mediates transmembrane efflux of many drugs. Since it is involved in multi-drug resistance activity in various cancer cells, the development of P-gp inhibitor is one of the major concerns in anticancer therapy. Human P-gp protein has at least two "functional" drug binding sites that are called "H" site and "R" site, hence it has multi-binding-specificities. Though the amino acid residues that constitute in drug binding pockets have been proposed by previous experimental evidences, the shapes and the binding poses are not revealed clearly yet. In this study, human P-gp structure was built by homology modeling with available crystal structure of mouse P-gp as a template and docking simulations were performed with inhibitors such as verapamil, hoechst33342, and rhodamine123 to construct the interaction between human P-gp and its inhibitors. The docking simulations were performed 500 times for each inhibitor, and then the interaction frequency of the amino acids at the binding poses was analyzed. With the analysis results, we proposed highly contributing residues that constitute binding pockets of the human P-gp for the inhibitors. Using the highly contributing residues, we proposed the locations and the shapes of verapamil binding site and "R" site, and suggested the possible position of "H" site.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.218-224
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• 2013

The aldo-keto reductases catalyze reduction reactions using various aliphatic and aromatic aldehydes/ketones. Most reductases require NADPH exclusively as their cofactors. However, NADPH is much more expensive and unstable than NADH. In this study, we attempted to change the five amino acid residues that interact with the 2'-phosphate group of the adenosine ribose of NADPH. These residues were selected based on a docking model of the YOL151W reductase and were substituted with other amino acids to develop NADH-utilizing enzymes. Ten mutants were constructed by site-directed mutagenesis and expressed in Escherichia coli. Among them, four mutants showed higher reductase activities than wild-type when using the NADH cofactor. Analysis of the kinetic parameters for the wild type and mutants indicated that the $k_{cat}/K_{m}$ value of the Asn9Glu mutant toward NADH increased 3-fold. A docking model was used to show that the carboxyl group of Glu 9 of the mutant formed an additional hydrogen bond with the 2'-hydroxyl group of adenosine ribose. The Asn9Glu mutant was able to produce (R)-ethyl-4-chloro-3-hydroxyl butanoate rapidly when using the NADH regeneration system.

• Bulletin of the Korean Chemical Society
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• 제33권6호
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• pp.1885-1889
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• 2012

Among 23 cytochrome P450s, CYP125A4 was proposed as a putative monooxygenase based on the high level of amino acid sequence homology (54% identity and 75% similarity) with the well characterized C27-steroid $Mycobacterium$ $tuberculosis$ CYP125A1. Utilizing MTBCYP125A1 as a template, homology modeling of SPCYP125A4 was conducted by Accelrys Discovery Studio 3.1 software. The modeled SPCYP125A4 structure with lowest energy value was subsequently assessed for its stereochemical quality and side-chain environment. The final model was generated by showing its active site through the molecular dynamics. The docking of steroids showed broad specificity of SPCYP125A4 with different orientation of ligand within active site facing the heme. One poses of C27-steroid with C26 facing the heme with distance of 3.734 ${\AA}$ from the Fe were predominant.

• EDISON SW 활용 경진대회 논문집
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• 제5회(2016년)
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• pp.90-95
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• 2016

Heat Shock 70kDa Protein 1-Like(HSPA1L)는 Heat-shock protein70(HSP70) family에 속하는 chaperone protein으로 polypeptide folding, assembly, protein degradation 등 다양한 biological processes에 관여하고 있다. HSPA1L은 human methyltransferase-like protein 21A(METTL21A)에 의해 lysine residue에 methylation이 일어나게 되는데, 암세포에서 일반적인 HSPA1L은 주로 세포질에서 발견되는 반면 methylated HSPA1L의 경우 주로 핵에서 발견이 됨으로써 HSPA1L methylation이 암 세포 성장에 중요할 역할을 할 것이라 추측되며 anti-cancer drug target으로 주목 받고 있다. 하지만 현재 HSPA1L의 구조가 부분적으로만 밝혀져 있어 HSPA1L와 METTL21A가 어떤 residue들이 interaction 하여 binding을 하는지에 대해서 아직 밝혀 지지 않았다. 이로 인해 anti-cancer drug target으로서의 연구에 제한이 있다. 이번 연구에서는 homology modeling(Galaxy-TBM, Galaxy-refine)을 통해 HSPA1L 전체 구조를 밝혀 낸 후, HSPA1L 와 METTL21A를 protein-protein docking을 통해 binding pose 예측을 하였다. 이러한 binding pose를 protein interaction analysis하여 HSPA1L과 METTL21A binding에 관여하는 중요 residue들을 밝혀 냈다. 이러한 structural information은 methylated HSPA1L와 암 세포 성장간의 연관성, 더 나아가 anti-cancer drug 개발로 까지도 이어 질 수 있을 것이라 생각한다.

• 통합자연과학논문집
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• 제13권4호
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• pp.170-180
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• 2020

Abnormal regulation, hyperphosphorylation, and aggregation of the tau protein are the hallmark of several types of dementia, including Alzheimer's Disease. Increased activity of Glycogen Synthase Kinase-3β (GSK-3β) in the Central Nervous System (CNS), increased the tau hyperphosphorylation and caused the neurofibrillary tangles (NFTs) formation in the brain cells. Over the last two decades, numerous adenosine triphosphate (ATP) competitive inhibitors have been discovered that show inhibitory activity against GSK-3β. But these compounds exhibited off-target effects which motivated researchers to find new GSK-3β inhibitors. In the present study, we have collected the dataset of 31 C-Glycosylflavones derivatives that showed inhibitory activity against GSK-3β. Among the dataset, the most active compound was docked with the GSK-3β and molecular dynamics (MD) simulation was performed for 50 ns. Based on the 50 ns MD pose of the most active compound, the other dataset compounds were sketched, minimized, and aligned. The 3D-QSAR based Comparative Molecular Field Analysis (CoMFA) model was developed, which showed a reasonable value of q2=0.664 and r2=0.920. The contour maps generated based on the CoMFA model elaborated on the favorable substitutions at the R2 position. This study could assist in the future development of new GSK-3β inhibitors.

• 한국축산식품학회지
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• 제43권1호
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• pp.184-194
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• 2023

Recently, interest in food-derived bioactive peptides as promising ingredients for the prevention and improvement of hypertension is increasing. The purpose of this study was to determine the structure and antihypertensive effect of an antioxidant peptide purified from velvet antler in a previous study and evaluate its potential as a various bioactive peptide. Molecular weight (MW) and amino acid sequences of the purified peptide were determined by quadrupole time-of-flight electrospray ionization mass spectroscopy. The angiotensin I-converting enzyme (ACE) inhibition activity of the purified peptide was assessed by enzyme reaction methods and in silico molecular docking analysis to determine the interaction between the purified peptide and ACE. Also, antihypertensive effect of the purified peptide in spontaneously hypertensive rats (SHRs) was investigated. The purified antioxidant peptide was identified to be a pentapeptide Asp-Asn-Arg-Tyr-Tyr with a MW of 730.31 Da. This pentapeptide showed potent inhibition activity against ACE (IC₅₀ value, 3.72 μM). Molecular docking studies revealed a good and stable binding affinity between purified peptide and ACE and indicated that the purified peptide could interact with HOH2570, ARG522, ARG124, GLU143, HIS387, TRP357, and GLU403 residues of ACE. Furthermore, oral administration of the pentapeptide significantly reduced blood pressure in SHRs. The pentapeptide derived from enzymatic hydrolysate of velvet antler is an excellent ACE inhibitor. It might be effectively applied as an animal-based functional food ingredient.

• Journal of Applied Biological Chemistry
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• 제53권4호
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• pp.225-231
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• 2010

기질분자로서 polyhydroxy 치환된 2-phenyl-l,4-benzopyrone 유도체(Flavones)(1-25)들의 hydroxyl 치환기($R_1-R_9$)가 변화함에 따른 Tyrosinase(PDB ID: oxy-form; 1WX2)에 대한 저해활성을 이해하기 위하여 분자도킹과 3차원적인 정량적 구조활성관계 (3D-QSARs: CoMFA 및 CoMSIA)가 연구되었다. 그 결과, 통계적으로 CoMFA 1 및 CoMSIA 1 모델이 가장 양호한 3D-QSARs 모델이었다. 또한, 순차 혼합화 분석결과로부터 CoMSIA 1 모델($dq^2'/dr_{yy'}^2$=1.009 및 $q^2$=0.511)이 우연상관성에 저촉되지 않는 최적화 모텔이었으며 최적화된 CoMSIA 1 모델의 tyrosinase에 대한 저해활성은 기질분자의 정전기장(51.4%)에 의존적이었다. Tyrosinase의 반응점에 대한 3D-QSAR 모델의 등고도는 수용체로서 tyrosinase과 저해제로서 2-phenyl-l,4-benzopyrone 기질분자 사이의 새로운 상호작용 관계를 이해하는 계기가 되었다. 그러므로 이 결과들은 새로운 잠재적인 tyrosinase 저해제의 최적화에 적용될 수 있을 것이다.

• 생명과학회지
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• 제33권11호
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• pp.876-886
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• 2023

두경부암(HNC)의 경우, 외과적 개입은 환자의 삶의 질에 심각한 영향을 미칠 수 있으며, 화학요법을 병행하게 된다. 그러나 화학요법에는 현저한 부작용이 있으므로 환자의 고통을 최소화하기 위한 보조 방법의 개발이 필요하다. 천궁(Ligusticum chuanxiong)은 동양 의학에서 뇌혈관 장애 및 두통에 사용되는 천연 허브이다. 본 연구에서는 네트워크 기반 약리학 및 분자 도킹 분석을 통해 천궁의 근본적인 항암기전을 예측하였다. 본 연구에서 HNC와 관련된 천궁의 공통 유전자를 밝혀내어 신경 활성 리간드의 대사 및 신경 전달 물질 경로와의 연관성을 확인했다. 본 연구는 천궁의 성분 중 하나인 (Z)-ligustilide 가 암세포 활성화에 관련된 heat shock protein 90의 ATP 결합 부위를 공유함을 입증했다. 이 결과는 천궁이 보조 항암제 개발을 위한 유망한 후보임을 시사하며, 향 후 더욱 새롭고 안전한 항암제의 연구개발에 과학적 근거를 제시하는 새로운 발견이다.