• 제목/요약/키워드: BioInformatics

검색결과 580건 처리시간 0.024초

Flavonoids as Substrates of Bacillus halodurans O-Methyltransferase

  • Jeong, Ki-Woong;Lee, Jee-Young;Kang, Dong-Il;Lee, Ju-Un;Hwang, Yong-Sic;Kim, Yang-Mee
    • Bulletin of the Korean Chemical Society
    • /
    • 제29권7호
    • /
    • pp.1311-1314
    • /
    • 2008
  • Bacillus halodurans O-methyltransferase (BhOMT) is an S-adenosylmethionine dependent methyltransferase. In our previous study, three dimensional structure of the BhOMT has been determined by comparative homology modeling and automated docking study showed that two hydroxyl groups at 3'- and 4'-position in Bring and structural rigidity of C-ring resulting from the double bond characters between C2 and C3 of flavonoid, were key factors for interaction with BhOMT. In the present study, BhOMT was cloned and expressed. Binding assay was performed on purified BhOMT using fluorescence experiments and binding affinity of luteolin, quercetin, fisetin, and myricetin were measured in the range of $10^7$. Fluorescence quenching experiments indicated that divalent cation plays a critical role on the metal-mediated electrostatic interactions between flavonoid and substrate binding site of BhOMT. Fluorescence study confirmed successfully the data obtained from the docking study and these results imply that hydroxyl group at 7-position of luteolin, quercetin, fisetin, and myricetin forms a stable hydrogen bonding with K211 and carboxyl oxygen of C-ring forms a stable hydrogen bonding with R170. Hydroxyl group at 3'-and 4'-position in the B-ring also has strong $Ca^{2+}$ mediated electrostatic interactions with BhOMT.

Construction of Microbial Fuel Cells Using Thermophilic Microorganisms, Bacillus licheniformis and Bacillus thermoglucosidasius

  • Choi, Young-Jin;Jung, Eun-Kyoung;Park, Hyun-Joo;Paik, Seung R.;Jung, Seun-Ho;Kim, Sung-Hyun
    • Bulletin of the Korean Chemical Society
    • /
    • 제25권6호
    • /
    • pp.813-818
    • /
    • 2004
  • A systematic study of microbial fuel cells comprised of thermophilic Bacillus licheniformis and Bacillus thermoglucosidasius has been carried out under various operating conditions. Substantial amount of electricity was generated when a redox mediator was used. Being affected by operation temperature, the maximum efficiency was obtained at 50$^{\circ}C$ with an open circuit voltage of ca. 0.7 V. While a small change around the optimum temperature did not make much effect on the cell performance, the rapid decrease in performance was observed above 70$^{\circ}C$. It was noticeable that fuel cell efficiency and discharge pattern strongly depended on the kind of carbon sources used in the initial culture medium. In the case of B. thermoglucosidasius, glucose alone was utilized constitutively as a substrate in the microbial fuel cell irrespective of used carbons sources. When B. licheniformis was cultivated with lactose as a carbon source, best charging characteristics were recorded. Trehalose, in particular, showed 41.2% coulombic efficiency when B. thermoglucosidasius was cultured in a starch-containing medium. Relatively good repetitive operation was possible with B. thermoglucosidasius cells up to 12 cycles using glucose as a carbon source, when they were cultured with lactose as an initial carbon source. This study demonstrates that highly efficient thermophilic microbial fuel cells can be constructed by a pertinent modulation of the operating conditions and by carefully selecting carbon sources used in the initial culture medium.

Inhibitory Effects of Naringenin, Kaempherol, and Apigenin on Cholesterol Biosynthesis in HepG2 and MCF-7 Cells

  • Kim, Kee-Tae;Yeo, Eun-Ju;Moon, Sun-Hee;Cho, Ssang-Goo;Han, Ye-Sun;Nah, Seung-Yeol;Paik, Hyun-Dong
    • Food Science and Biotechnology
    • /
    • 제17권6호
    • /
    • pp.1361-1364
    • /
    • 2008
  • The inhibitory effects of naringenin, kaempherol, and apigenin on the production of cholesterol in HepG2 KCLB 88065 and MCF-7 KCLB 30022 cells were evaluated. In this study, quercetin was used as a reference reagent. After incubation for 3 days, fat-soluble contents of both cell types were extracted by using the Folch method and the cholesterol contents in both cultured cells were determined by high performance liquid chromatography. The concentration of cholesterol in untreated each tissue cells was $12.2{\pm}0.11$ and $8.83{\pm}0.12\;mg/g$ of lipid, respectively. The total concentration of each flavonoid was adjusted to 0, 35, or $350{\mu}M$ in the culture broth. As the results, the addition of 2% methanol and dimethyl sulfoxide (DMSO) to the media (control for flavonoid solvents) did not significantly affect cell growth; however, DMSO caused an increase in the production of cholesterol. Each flavonoid inhibited the production of cholesterol in both HepG2 and MCF-7 cells at the concentration of $35{\mu}M$ above. In addition, the inhibitory effect of kaempherol on the production of cholesterol in these cells was greater than the other flavonoids tested and HepG2 cells are more sensitive to flavonoids than MCF-7. From the results, the inhibitory effects of flavonoids on cholesterol production are different depending on the cell type.

Screening of Antiviral Medicinal Plants against Avian Influenza Virus H1N1 for Food Safety

  • Lee, Jang-Hyun;Van, Nguyen Dinh; Ma, Jin-Yeul;Kim, Young-Bong;Kim, Soo-Ki;Paik, Hyun-Dong
    • 한국축산식품학회지
    • /
    • 제30권2호
    • /
    • pp.345-350
    • /
    • 2010
  • Various extracts from 30 medicinal plants were evaluated for their antiviral activity against influenza virus A/Puerto Rico/8/34 (H1N1) and cytotoxicity in MDCK cell culture. The plant material (30 g) was extracted with methanol (300 mL) at room temperature for 24 h, after which the methanolic extracts were filtered, evaporated, and subsequently lyophilized. Evaluation of the potential antiviral activity was conducted by a viral replication inhibition test. Among these medicinal plants, Tussilago farfara, Brassica juncea, Prunus armeniaca, Astragalus membranaceus, Patrinia villosa, and Citrus unshiu showed marked antiviral activity against influenza virus A/H1N1 at concentrations ranging from 0.15625 mg/mL to 1.25 mg/mL, 0.3125 mg/mL to 10 mg/mL, 5 mg/mL to 10 mg/mL, 0.625 mg/mL to 10 mg/mL, 0.625 mg/mL to 10 mg/mL, and 0.3125 mg/mL to 5 mg/mL, respectively. The extracts of Tussilago farfara showed cytotoxicity at concentrations greater than 2.5 mg/mL, whereas the other five main extracts showed no cytotoxicity at concentrations of 10 mg/mL. Taken together, the present results indicated that methanolic extracts of the six main plants might be useful for the treatment of influenza virus H1N1.

Antimicrobial, Anti-inflammatory, and Anti-oxidative Activities of Scilla scilloides (Lindl.) Druce Root Extract

  • Yeo, Eun-Ju;Kim, Kee-Tae;Han, Ye-Sun;Nah, Seung-Yeol;Paik, Hyun-Dong
    • Food Science and Biotechnology
    • /
    • 제15권4호
    • /
    • pp.639-642
    • /
    • 2006
  • The root extract of Scilla scilloides (which has been used as a traditional folk medicine in Korea) was evaluated with regard to antimicrobial, anti-inflammatory, and anti-oxidative activities. The roots of S. scilloides were minced and extracted with 95% ethanol (root:ethanol=25:75, w/v). The inhibitory effects of S. scilloides root extract on the growth of Staphylococcus aureus ATCC 35556, Salmonella enteritidis ATCC 12021, Escherichia coli O157:H7, and Candida parapsilosis KCCM 35428 were tested. The results indicate that the antimicrobial effects of both 0.1 and 1.0% extract of S. scilloides were greater against the growth of S. aureus ATCC 35556 and C. parapsilosis KCCM 35428 than the growth of S. enteritidis ATCC 12021 and E. coli O157:H7. The anti-inflammatory effects were evaluated by measurement of the inhibition of hyaluronidase activity in vitro. It appears that both 0.1 and 1.0% concentrations of extract have inhibitory effects on hyaluronidase relative to the control. Finally, the anti-oxidative effect of 1.0 and 10% extract solutions were measured according to the thiocyanate method and were compared with 1.0% BHT. The results indicate that the anti-oxidative effect of 10% S. scilloides root extract (anti-oxidative index (AOI); $72.3{\pm}4.2$) is not significantly different from that of 1.0% BHA (AOI; $76.8{\pm}3.5$) (p<0.05). However, it appears that the anti-oxidative effect of S. scilloides root extract is at least three-fold greater than that of BHA when accounting for the amount of dissolved solids in each.

H9 Induces Apoptosis via the Intrinsic Pathway in Non-Small-Cell Lung Cancer A549 Cells

  • Kwon, Sae-Bom;Kim, Min-Je;Sun Young, Ham;Park, Ga Wan;Choi, Kang-Duk;Jung, Seung Hyun;Do-Young, Yoon
    • Journal of Microbiology and Biotechnology
    • /
    • 제25권3호
    • /
    • pp.343-352
    • /
    • 2015
  • H9 is an ethanol extract prepared from nine traditional/medicinal herbs. This study was focused on the anticancer effect of H9 in non-small-cell lung cancer cells. The effects of H9 on cell viability, apoptosis, mitochondrial membrane potential (MMP; ${\Delta}\psi_{m}$), and apoptosisrelated protein expression were investigated in A549 human lung cancer cells. In this study, H9-induced apoptosis was confirmed by propidium iodide staining, expression levels of mRNA were determined by reverse transcriptase polymerase chain reaction, protein expression levels were checked by western blot analysis, and MMP (${\Delta}\psi_{m}$) was measured by JC-1 staining. Our results indicated that H9 decreased the viability of A549 cells and induced cell morphological changes in a dose-dependent manner. H9 also altered expression levels of molecules involved in the intrinsic signaling pathway. H9 inhibited Bcl-xL expression, whereas Bax expression was enhanced and cytochrome C was released. Furthermore, H9 treatment led to the activation of caspase-3/caspase-9 and proteolytic cleavage of poly(ADP-ribose) polymerase; the MMP was collapsed by H9. However, the expression levels of extrinsic pathway molecules such as Fas/FasL, TRAIL/TRAIL-R, DR5, and Fas-associated death receptor were downregulated by H9. These results indicated that H9 inhibited proliferation and induced apoptosis by activating intrinsic pathways but not extrinsic pathways in human lung cancer cells. Our results suggest that H9 can be used as an alternative remedy for human non-small-cell lung cancer.

Cyclosophoraose as a Novel Chiral Stationary Phase for Enantioseparation

  • JUNG, YUN-JUNG;LEE, SANG-HOO;PAIK, SEUNG-R.;JUNG, SEUN-HO
    • Journal of Microbiology and Biotechnology
    • /
    • 제14권6호
    • /
    • pp.1338-1342
    • /
    • 2004
  • Cyclosophoraoses (Cys), cyclic ${\beta}-(1{\rightarrow}2)-D-glucans$ produced by Rhizobium meliloti 2011, were used as a novel chiral stationary phase for the enantiomeric separation. A novel Cys stationary phase, chemically immobilized onto porous silica via aminopropyltrimethoxysilane as a molecular linker, showed good separation for each racemate of bupivacain (separation factor, $\alpha$=1.3), propranolol ($\alpha$=1.3), and fenoprofen ($\alpha$=2.9), respectively, under the mobile phase of water: methanol (80:20, v/v) at a constant flow rate of 0.9 ml/min at pH7.

Biological Synthesis of 7-O-Methyl Apigenin from Naringenin Using Escherichia coli Expressing Two Genes

  • Jeon, Young-Min;Kim, Bong-Gyu;Ahn, Joong-Hoon
    • Journal of Microbiology and Biotechnology
    • /
    • 제19권5호
    • /
    • pp.491-494
    • /
    • 2009
  • Within the secondary metabolite class of flavonoids, which consist of more than 10,000 known structures, flavones define one of the largest subgroups. The diverse function of flavones in plants as well as their various roles in the interaction with other organisms offers many potential applications including in human nutrition and pharmacology. We used two genes, flavone synthase (PFNS-l) that converts naringenin into apigenin and flavone 7-O-methyltransferase (POMT-7) that converts apigenin into 7-O-methyl apigenin, to synthesize 7-O-methyl apigenenin from naringenin. The PFNS-l gene was subcloned into the E. coli expression vector pGEX and POMT-7 was subcloned into the pRSF vector. Since both constructs contain different replication origins and selection markers, they were cotransformed into E. coli. Using E. coli transformants harboring both PFNS-l and POMT-7, naringenin could be converted into 7-O-methyl apigenin, genkwanin.

Antifungal Activities Against Plasmodiophora brassicae Causing Club Root

  • Kim, Bum-Joon;Choi, Gyung-Ja;Cho, Kwang-Yun;Yang, Hee-Jung;Shin, Choon-Shik;Lee, Chul-Hoon;Lim, Yoong-Ho
    • Journal of Microbiology and Biotechnology
    • /
    • 제12권6호
    • /
    • pp.1022-1025
    • /
    • 2002
  • Club root is one of the major diseases that occur in crucifers. It is caused by Plasmodiophora brassicae. In order to discover microbial biopesticides against P. brassicae, forty-eight Streptomyces isolated from soil were screened. Among these, three strains showed excellent pesticidal activities. We report results on in vivo screening with fermentation broths of these strains and identification of the strain taxa.