• 생명과학회지
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• 제17권12호
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• pp.1760-1765
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• 2007

생명체 내에서 일어나는 거의 모든 반응은 단백질이 촉진하거나 수행한다. 단백질은 세포질과 소포체에서 합성될 때 엄격하게 조절된다. 그러나, 새로이 합성된 모든 단백질이 살아남아서 생명을 유지시키는 기능에 관여하게 되지는 않는다. 가장 알맞은 생리학적 in vitro 실험 조건에서 새로이 합성된 단백질의 약 3분의 1 정도는 합성되자마자 proteasome에 의해 빠르게 분해된다고 보고되었다. 또한, 단백질은 합성이 성공적으로 이루어진 이후에는 3차원 구조를 갖기 위해 접힘(folding)이 이루어져야 하고, subunit들은 assembly 과정을 거쳐야 비로소 성숙된 단백질로서 기능을 하게 된다. 어떤 단백질군은 자연적으로 접힘이 일어나는 반면 어떤 단백질군은 분자 샤페론(molecular chaperones)과 folding enzymes의 도움을 받아야만 접힘이 일어난다. 분자 샤페론은 세포 전역에 분포하고 있으며, 세균에서부터 고등 동식물에 이르기까지 모든 생명체에 존재한다. 이들 중 Hsp70군은 많이 연구된 분자 샤페론으로서 지난 10여년 동안 조절인자들이 새로이 발견되어 작용 mechanism이 보다 자세히 밝혀졌다. 본 총설에서 Hsp70군과 그 조절인자들에 대한 전반적인 서술을 하였으며, 이들의 기능이 분자 샤페론 기능 외에 생체 내에서 중요한 기능들이 새롭게 밝혀지고 있어 이들의 작용 mechanism을 조명함으로 이해를 돕고자 한다.

• Journal of Ginseng Research
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• 제47권2호
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• pp.228-236
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• 2023

Background: QiShen YiQi pills (QSYQ) is a Traditional Chinese Medicine (TCM) formula, which has a significant effect on the treatment of patients with myocardial infarction (MI) in clinical practice. However, the molecular mechanism of QSYQ regulation pyroptosis after MI is still not fully known. Hence, this study was designed to reveal the mechanism of the active ingredient in QSYQ. Methods: Integrated approach of network pharmacology and molecular docking, were conducted to screen active components and corresponding common target genes of QSYQ in intervening pyroptosis after MI. Subsequently, STRING and Cytoscape were applied to construct a PPI network, and obtain candidate active compounds. Molecular docking was performed to verify the binding ability of candidate components to pyroptosis proteins and oxygen-glucose deprivation (OGD) induced cardiomyocytes injuries were applied to explore the protective effect and mechanism of the candidate drug. Results: Two drug-likeness compounds were preliminarily selected, and the binding capacity between Ginsenoside Rh2 (Rh2) and key target High Mobility Group Box 1 (HMGB1)was validated in the form of hydrogen bonding. 2 μM Rh2 prevented OGD-induced H9c2 death and reduced IL-18 and IL-1β levels, possibly by decreasing the activation of the NLRP3 inflammasome, inhibiting the expression of p12-caspase1, and attenuating the level of pyroptosis executive protein GSDMD-N. Conclusions: We propose that Rh2 of QSYQ can protect myocardial cells partially by ameliorating pyroptosis, which seems to have a new insight regarding the therapeutic potential for MI.

• Journal of Photoscience
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• 제9권2호
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• pp.150-153
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• 2002

Solar UV light is a well-known carcinogen. UVA radiation is probably carcinogenic to humans. In addition, recent investigations point to the importance of UVA irradiation in the photoaging. We investigated the mechanism of sequence- specific DNA damage using $\^$32/P-Iabeled DNA fragments in relation to carcinogenesis and aging. Furthermore, we investigated whether UVA accelerates the telomere shortening in human WI-38 fibroblasts. The exposure of double- stranded DNA fragments to 365 nm light in the presence of endogenous sensitizers produced sequence-specific cleavage at the 5' site of 5'-GG-3' and 5'-GGG-3' sequences. In addition, HPLC analysis revealed that sensitizers plus 365 nm light increased the 8-oxodG content of double-stranded DNA. We discuss the mechanisms of guanine-specific DNA damagecaused by excited photosensitizers in relation to carcinogenesis and aging.

• Natural Product Sciences
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• 제19권2호
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• pp.120-126
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• 2013

Natural products have always been a pivotal source of new drug development. Dry roots of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae) is a perennial herb and is also known as Bang Pung in traditional medicine. Numerous in vitro and in vivo studies have revealed the diverse pharmacological effects of S. divaricata and its role in the treatment of various diseases. This herb has exhibited significant inhibitory effects against inflammation and associated disorders. The present study explored the ethnopharmacological applications and molecular mechanisms behind the anti-inflammatory effects of S. divaricata herb and a single compound blockade of multi-signaling inflammatory cascades. Taken together, this review provides insight into the potential role of S. divaricata against various inflammatory diseases.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2222-2226
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• 2011

Amylase is a digestive enzyme that catalyses the starch into sugar. It has been reported that the green tea flavonoid (or polyphenols) (-)-epigallocatechin 3-gallate (EGCG) inhibits human salivary ${\alpha}$-amylase (HSA) and induced anti-nutritional effects. In this study, we performed docking study for seven EGCG-like flavonoids and HSA to understand the interaction mechanism of HSA and EGCG and suggest new possible flavonoid inhibitors of HSA. As a result, EGCG and (-)-epicatechin gallate (ECG) bind to HSA with complex hydrogen bonding interactions. These hydrogen bonding interactions are important for inhibitory activity of EGCG against HSA. We suggested that ECG can be a potent inhibitor of HSA. This study will be helpful to understand the mechanism of inhibition of HSA by EGCG and give insights to develop therapeutic strategies against diabetes.

• 대한화학회지
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• 제19권3호
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• pp.179-185
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• 1975

방향족 치환반응을 모형과하여 유사분자 착물이 천이상태가 될수있음을 단수 Huckel법으로 증명하고 새로운 방향족 치환반응의 기구를 제안하였다. 아울러 이 유사분자 착물을 양자역학적 선동법을 이용하여 안정화 에너지식을 유도하고 많은 탄소화합물의 안정화 에너지식을 유도하고 많은 탄소화합물의 안정화 에너지를 구하였다. 이 안정화 에너지로 어떤 방향족 화합물이 유사분자 착물을 형성하는 위치와 그 화합물의 치환반응의 결합 시약이 방향족 화합물에 부가반응이 일어나는 반응에까지 널리 설명할 수 있는 이점이 있다.

• 펄프종이기술
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• 제33권3호
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• pp.24-28
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• 2001

The utilization of wastepaper as a papermaking raw material is everlastingly required for the environmental protection of earth. However the recycling of wastepaper for this purpose cause another problem such as the increasing of the load of wastewater treatment, lower strength properties of paper, and poor printability, etc. The interest in the development of the environmentally friendly deinking technology is increased continuously. Thus, our research team have tried to apply the ozone to the deinking of white ledger and ONP, and obtained the positive results which can be considered as an alternative method for the conventional deinking method. The purpose of this study is to investigate the mechanism of ozone deinking. Styrene acrylate and polystyrene were treated with ozone and measured the change of molecular weight with the GPC. The molecular weight distribution obtained with GPC showed only slight increase by the ozone treatment, and gel formation by the polymerization was observed. Therefore the removal of ink particles with ozone treatment seems to be facilitated by the increase of the brittleness and decrease of adhesive property.

• 한국진공학회지
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• 제4권S2호
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• pp.139-147
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• 1995

The mechanism of the ionized cluster beam deposition has been studied using Molecular Dynamics Simulation. The Embedded Atom Method(EAM) potential were used in the simulation. The impact of a Au95-cluster on Au(100) substrate was studied for the impact energies 0.15-10eV/atom. The dependency of the impact energy of cluster beam was observed. For the cluster energy impact of 10eV per atom, the defects on surface were created and the cluster embedded into substrate as an amorphous state. For the energy of 0.5eV per atom, the defect free homoepitaxial growth was observed and atomic scale nucleation was formated, which are in good agreement with experiment. Thus molecular dynamics simulation is very useful to study the mechanism of the ionized cluster beam deposition.

• Biomolecules & Therapeutics
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• 제30권6호
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• pp.490-500
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• 2022

Aging is defined as physiological dysfunction of the body and a key risk factor for human diseases. During the aging process, cellular senescence occurs in response to various extrinsic and intrinsic factors such as radiation-induced DNA damage, the activation of oncogenes, and oxidative stress. These senescent cells accumulate in many tissues and exhibit diverse phenotypes, such as resistance to apoptosis, production of senescence-associated secretory phenotype, cellular flattening, and cellular hypertrophy. They also induce abnormal dysfunction of the microenvironment and damage neighboring cells, eventually causing harmful effects in the development of various chronic diseases such as diabetes, cancer, and neurodegenerative diseases. Thus, pharmacological interventions targeting senescent cells, called senotherapeutics, have been extensively studied. These senotherapeutics provide a novel strategy for extending the health span and improving age-related diseases. In this review, we discuss the current progress in understanding the molecular mechanisms of senotherapeutics and provide insights for developing senotherapeutics.

• Corrosion Science and Technology
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• 제21권1호
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• pp.21-31
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• 2022

Potentiodynamic polarization, EIS measurements, quantum chemical calculations, and molecular dynamic simulations were used to investigate the corrosion behavior of mild steel in 0.5 M aqueous hydrochloric acid medium in the presence or absence of nystatin drug. Potentiodynamic tests suggested that this molecule could act as a mixed inhibitor due to its adsorption on the mild steel surface. The objective of this study was to exploit theoretical calculations to gain a better understanding mechanism of inhibition. Calculating the adsorption behavior of the investigated molecule on Fe (1 1 0) surface was accomplished using Monte Carlo simulation. Molecules were also investigated using Density Functional Theory (DFT), specifically PBE functional, in order to identify the link between molecular structure and corrosion inhibition behavior of the compound under investigation. Adsorption energies between nystatin and iron were estimated more accurately by utilizing Molecular Mechanics calculation with Periodic Boundary Conditions (PBC). Estimated theoretical parameters significantly assisted our understanding of the corrosion inhibition mechanism exhibited by this molecule. They were found to be in accord with experimental results.