• Title/Summary/Keyword: BMIC

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In Silico Study of the Ion Channel Formed by Tolaasin I Produced by Pseudomonas tolaasii

  • Jo, Geun-Hyeong;Hwang, Do-Seok;Lee, Sun-Hee;Woo, Yoon-Kyung;Hyun, Ji-Ye;Yong, Yeon-Joong;Kang, Kyung-Rai;Kim, Dong-Woon;Lim, Yoong-Ho
    • Journal of Microbiology and Biotechnology
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    • v.21 no.10
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    • pp.1097-1100
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    • 2011

  • A toxin produced by Pseudomonas tolaasii, tolaasin, causes brown blotch disease in mushrooms. Tolaasin forms pores on the cellular membrane and destroys cell structure. Inhibiting the ability of tolaasin to form ion channels may be an effective method to protect against attack by tolaasin. However, it is first necessary to elucidate the three-dimensional structure of the ion channels formed by tolaasin. In this study, the structure of the tolaasin ion channel was determined in silico based on data obtained from nuclear magnetic resonance experiments.

  • https://doi.org/10.4014/jmb.1103.03026 인용 PDF KSCI

Characterization of an O-Methyltransferase from Streptomyces avermitilis MA-4680

  • Yoon, Young-Dae;Park, Young-Hee;Yi, Yong-Sub;Lee, Young-Shim;Jo, Geun-Hyeong;Park, Jun-Cheol;Ahn, Joong-Hoon;Lim, Yoong-Ho
    • Journal of Microbiology and Biotechnology
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    • v.20 no.9
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    • pp.1359-1366
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    • 2010

  • A search of the Streptomyces avermitilis genome reveals that its closest homologs are several O-methyltransferases. Among them, one gene (viz., saomt5) was cloned into the pET-15b expression vector by polymerase chain reaction using sequence-specific oligonucleotide primers. Biochemical characterization with the recombinant protein showed that SaOMT5 was S-adenosyl-L-methionine-dependent Omethyltransferase. Several compounds were tested as substrates of SaOMT5. As a result, SaOMT5 catalyzed O-methylation of flavonoids such as 6,7-dihydroxyflavone, 2',3'-dihydroxyflavone, 3',4'-dihydroxyflavone, quercetin, and 7,8-dihydroxyflavone, and phenolic compounds such as caffeic acid and caffeoyl Co-A. These reaction products were analyzed by TLC, HPLC, LC/MS, and NMR spectroscopy. In addition, SaOMT5 could convert phenolic compounds containing ortho-dihydroxy groups into O-methylated compounds, and 6,7-dihydroxyflavone was known to be the best substrate. SaOMT5 converted 6,7-dihydroxyflavone into 6-hydroxy-7-methoxyflavone and 7-hydroxy-6-methoxyflavone, and caffeic acid into ferulic acid and isoferulic acid, respectively. Moreover, SaOMT5 turned out to be a $Mg^{2+}$-dependent OMT, and the effect of $Mg^{2+}$ ion on its activity was five times greater than those of $Ca^{2+}$, $Fe^{2+}$, and $Cu^{2+}$ ions, EDTA, and metal-free medium.

  • https://doi.org/10.4014/jmb.1005.05012 인용 PDF KSCI

Identification of the active components inhibiting the expression of matrix metallopeptidase-9 by TNFα in ethyl acetate extract of Euphorbia humifusa Willd

  • Ahn, Seunghyun;Jung, Hyeryoung;Jung, Yearam;Lee, Junho;Shin, Soon Young;Lim, Yoongho;Lee, Young Han
    • Journal of Applied Biological Chemistry
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    • v.62 no.4
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    • pp.367-374
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    • 2019

  • Euphorbia humifusa Willd (EuH), called Ttang-Bin-Dae in Korea, is a traditional medicinal plant widely used for its anti-inflammatory and antiviral activity. Ethyl acetate (EA) extracts of EuH (EA/EuH) inhibit invasion and metastasis by inhibiting tumor necrosis factor TNFá-induced matrix metalloproteinases (MMP)-9 expression in human breast cancer cells. However, the bioactive components of EA/EuH mediating the inhibition of MMP-9 expression have not been identified. In the present study, three bioactive constituents of EA/EuH were isolated using high-performance liquid chromatography. Nuclear magnetic resonance spectroscopy revealed isoquercetin, avicularin, and astragalin as the bioactive compounds responsible for preventing TNFα-induced MMP-9 mRNA expression in breast cancer cells. These findings suggest that isoquercetin, avicularin, and astragalin could be used as valuable anti-metastatic agents against metastatic cancers.

  • https://doi.org/10.3839/jabc.2019.051 인용 PDF KSCI