• Title/Summary/Keyword: biological molecules

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Structure-Based Virtual Screening of Protein Tyrosine Phosphatase Inhibitors: Significance, Challenges, and Solutions

  • Reddy, Rallabandi Harikrishna;Kim, Hackyoung;Cha, Seungbin;Lee, Bongsoo;Kim, Young Jun
    • Journal of Microbiology and Biotechnology
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    • v.27 no.5
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    • pp.878-895
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    • 2017
  • Phosphorylation, a critical mechanism in biological systems, is estimated to be indispensable for about 30% of key biological activities, such as cell cycle progression, migration, and division. It is synergistically balanced by kinases and phosphatases, and any deviation from this balance leads to disease conditions. Pathway or biological activity-based abnormalities in phosphorylation and the type of involved phosphatase influence the outcome, and cause diverse diseases ranging from diabetes, rheumatoid arthritis, and numerous cancers. Protein tyrosine phosphatases (PTPs) are of prime importance in the process of dephosphorylation and catalyze several biological functions. Abnormal PTP activities are reported to result in several human diseases. Consequently, there is an increased demand for potential PTP inhibitory small molecules. Several strategies in structure-based drug designing techniques for potential inhibitory small molecules of PTPs have been explored along with traditional drug designing methods in order to overcome the hurdles in PTP inhibitor discovery. In this review, we discuss druggable PTPs and structure-based virtual screening efforts for successful PTP inhibitor design.

The Role of Extracellular Vesicles in Senescence

  • Oh, Chaehwan;Koh, Dahyeon;Jeon, Hyeong Bin;Kim, Kyoung Mi
    • Molecules and Cells
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    • v.45 no.9
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    • pp.603-609
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    • 2022
  • Cells can communicate in a variety of ways, such as by contacting each other or by secreting certain factors. Recently, extracellular vesicles (EVs) have been proposed to be mediators of cell communication. EVs are small vesicles with a lipid bilayer membrane that are secreted by cells and contain DNA, RNAs, lipids, and proteins. These EVs are secreted from various cell types and can migrate and be internalized by recipient cells that are the same or different than those that secrete them. EVs harboring various components are involved in regulating gene expression in recipient cells. These EVs may also play important roles in the senescence of cells and the accumulation of senescent cells in the body. Studies on the function of EVs in senescent cells and the mechanisms through which nonsenescent and senescent cells communicate through EVs are being actively conducted. Here, we summarize studies suggesting that EVs secreted from senescent cells can promote the senescence of other cells and that EVs secreted from nonsenescent cells can rejuvenate senescent cells. In addition, we discuss the functional components (proteins, RNAs, and other molecules) enclosed in EVs that enter recipient cells.

High-energy Proton Irradiated Few Layer Graphene Devices (고에너지 양성자에 의해 결함을 증가시킨 그래핀 소자의 전기적 특성 변화 연구)

  • Kim, Hong-Yeol;Kim, Ji-Hyun
    • Korean Chemical Engineering Research
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    • v.49 no.3
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    • pp.297-300
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    • 2011
  • High energy proton irradiations were performed on graphene devices to increase the number of defects intentionally. Proton energy and fluence were 6 MeV and $5{\times}10^{15}\;cm^{-2}$, respectively. The defects in few layer graphene layer created by proton irradiations captured oxygen molecules that acted as p-type dopants. After the vacuum annealing, hole mobility was enhanced by the recovery of the defects and the desorption of the oxygen molecules. However, the drain current decreased after vacuum annealing due to the removal of the dopant molecules.