• Journal of Ginseng Research
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• 제13권1호
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• pp.37-41
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• 1989

Benzo(a)pyrene(BP)의 monooxygenase(AHH)에 의해서 생성된 반응성 대사물질들의 in vitro DNA와의 결합 및 BP 대사에 관여하는 효소들의 활성도에 미치는 인삼 물추출물의 영향을 조사하였으며, DNA-BP metabolite adduct들은 Sephadex LH-20 column으로 chromatography하여 5개의 major peak 들을 얻었다. 이 peak 들을 극성이 큰 순서대로 A부터 E까지 임의로 정하고 5개의 peak들을 7,8-diol-9,10-oxide(A), 7,8-oxide(B). 4,5-oxide(C), 9-HO-BP(D & E) adduct들로 잠정적으로 확인하였다. Peak A, C, D 그리고 E는 각각 대조군의 30, 15, 20 그리고 30%로 감소되었으며 peak B는 의미있는 변화를 보이지 않았다. DNA-BP 결합 억제와 관련하여 in vitro와 in vivo 투여시의 경향이 유사하여 EH의 활성도만 BP투여 대조군보다 38%정도 의미있게 유도되었다.

• Toxicological Research
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• 제15권1호
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• pp.95-101
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• 1999

Cytochrome P450 (CYP) 3A4 metabolizes aflatoxin B1 (AFB1) to AFB1-exo-8,9-epoxide (8,9-epoxidation) and aflatoxin Q1 (AFQ1; 3$\alpha$-hydroxylation) simultaneously. We investigated whether each metabolite was formed via its own binding site of CAP3A4 active site. Kinetics of the formation of the two metabolites were sigmoidal and consistent with the kinetics of substrate activation. The HIll model predicted that two substrate binding wites are involved in the oxidationof AFB1 by CYP3A4. Dehydronifedipine, a metabolite of nifedipine generated by CYP3A4, inhibited the formation of AFQ1 without any inhibition in the formation of AFB1-exo-8,9-epoxidation. Dehydronifedipine was found to act as a reversible competitive inhibitor against 3$\alpha$-hydroxylation of AFB1. Vmax and S0.5 of the 8,9-epoxidation were not changed in the presence of 0, 50, or 100 $\mu\textrm{M}$ dehydronifedipine. S0.5 of 3$\alpha$-hydroxylation was increased from 58$\pm$4 $\mu\textrm{M}$ to 111$\pm$8 $\mu\textrm{M}$ in the presence of 100 $\mu\textrm{M}$ nifedipine whereas Vmax was not changed. These results suggest that there exist two independent binding sites in the active site of CAP3A4 . One binding site is responsible for AFB1-exo-8,9-epoxidation and the other is involved in 3$\alpha$-hydroxylation of AFB1. Dehydronifedipine might selectively bind to the site which is responsible for the formation of AFQ1 in the active site of CYP3A4.

• 약학회지
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• 제36권2호
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• pp.188-190
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• 1992

Two clones of monconal antibodies(Co-1 and Co-2) against BSA-benzoylecgonine(BSABE) were produced. Both monoclonal antibodies showed high binding affinity to BSA-BE. Observing from ELISA inhibition assay, Co-1 reacted only weakly with soluble benzoylecgonine, while Co-2 showed considerable reactivity with soluble benzoylecgonine.

• 한국미생물·생명공학회지
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• 제47권1호
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• pp.96-104
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• 2019

Beauveria bassiana, one of the most common entomopathogenic fungi, has been isolated, pre defined and characterized in-house from soil of tea cultivation area. Experiments have been performed to verify the presence of chitinase as intracellular metabolite and its release as extracellular product rendering the spores with biopesticide activity. Although there are many responsible enzymes for the pest killer action of B. bassiana, binding property of chitinase depending on presence as well as absence of serine supplemented in the media has been studied with respect to the production and kinetics. A programmed investigation conclusively indicates that the isolated spore (hyphae) of B. bassiana has been metabolically enriched with the enzyme chitinase in presence of an externally added amino acid serine with its inhibitory kinetics.

• Journal of Pharmaceutical Investigation
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• 제15권1호
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• pp.1-7
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• 1985

Previous studies show that the free (unbound) fraction of disopyramide in human serum is drug concentration dependent~ at corresponding serum disopyramide concentrations that are achieved clinically. $^1^{\sim}^3^)\;Moreover$, disopyramide free fraction values vary several fold at any given drug concentration in human serum and tend to decrease as serum cocentrations of alpha-I-acid glycoprotein(AAG) incrase.$^4^)$ A recent $study^5^)$ demonstrates that the free fraction of disopyramide inhuman serum increases almost 2-fold following the addition of $14.4{\mu}M/L$ mono-N-dealkyldisopyramide. These studies and others. $^6^),\;^7^)$ prompted the present investigation to characterize the protein binding of disopyramide in human serum and solutions of AAG in the presence of mono-N-dealkyldisopyramide (a major metabolite of, disopyramide) and to determine the utility of using commercially available alpha-I-acid glycoprotein for drug protein binding displacement studies. Because many basic and acidic compounds are known to bind to alpha-I-acid $glycoprotein^8^)$ the present study. was performed to determine whteher commercially available AAG would provide a convenient protein source for such binding studies.

• Toxicological Research
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• 제16권3호
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• pp.221-227
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• 2000

A 6-sulfooxymethylbenzo[a]pyrene (SMBP), the ultimate metabolite of methyl-substituted benzo[a]pyrene (BP), has been found to be carcinogenic in mice. These properties may be attributable to its strong reactivity with cellular macromolecules such as DNA. However, serum and its major constituent albumin attenuated significantly the cytotoxicity and mutagenicity of 5MBP in bacterial and mammalian cell systems. This inhibitory activity of serum against 5MBP-induced cytotoxicity and mutagenicity in Chinese hamster V79 cells appears to be caused by the reduced macromolecular adducts such as DNA and proteins, but serum failed to reduce 5MBP binding to naked calf thymus DNA. A number of proteins in the serum could act as nucleophiles that are able to intercept reactive chemicals through covalent binding. Albumin present in the plasma seems to be one of major components responsible for direct binding with 5MBp, thereby reducing its reactivity to genetic materials. We here determined which fraction is preferential for 5MBP binding through fractionation of 5MBP-treated serum with ammonium sulfate. The albumin-containing fraction had slightly more affinity for 5MBP than the immunoglobulin-containing fraction. Our results indicate that the covalent modification of plasma proteins may reduce 5MBP-induced damage.

• Journal of Ginseng Research
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• 제13권1호
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• pp.42-48
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• 1989

PAH 계 화합물들의 Bay region diol epoxide 들의 target tissue에 대한 결합은 암유발과 관련 되어 있다. 본 논문에서는 ICR mice의 간에서의 BP-DNA-adduct 생성에 미치는 poly acetylene 화합물인 panaxynol 과 panaxydol 의 효과를 조사하였 다. Panaxynol 과 panaxydol 을 전처리한 ICR mice 의 간 마이크로좀을 포함하는 incubation system 은 calf thymus DNA 에 대한 BP binding을 뚜렷이 감소시켰다. [$^3H$]-BP($300\mu$Ci/21nmoles/0.1ml DMSO. i. v. ) 즐 mice 에 주사 후 24시간 후에 간 DNA 에서의 방사능을 측정하였다. HPLC 에 의해 cochromatography 한 두개의 standard marker (acetophenone. bytyrophenone)을 사이에 나타나는 DNA adduct 들을 잠정적으로 확인한 결과 (-) BP-7.8-diol로부터 생성되는 major adduct 인 (+) BP-diol epoxide I: dGuo adduct (peak II)는 대조군보다 약 22% 감소된 반면에 minor adduct 인 (-) BP-diol epoxide I: dGuo adduct (peak III)는 대조군의 69%로 감소되었다. 그리고 (+) BP-7, 8-diol로부 터 생성되는 minor adduct 인 BP-diol epoxide I II : Guo adduct (peak IV)는 대조군의 58%로 감소되었다. 이러한 결과는 panaxydol이 ($\pm$) B BP-7,8-diol로부터 일반적으로 생성되는 adduct들 중 major보다는 minor adduct들의 생성에 더 많이 관석했음을 보여준다.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.186.2-186.2
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• 2003

PPARs (peroxisome proliferator activated receptors) are member of nuclear hormone receptors superfamily. Activations of PPARs upon binding with ligands modulate glucose metabolite, differentiation of adipocyte, inflammation response, and so on. Thiazolidinedione analog is one of the potential antidiabetic drug that binds and activates PPAR selectively and enhances insulin sensitivity. In an effort to develop novel and effective antidiabetic thiazolidindione analogs, we have synthesized tetrahydroquinoline and para-substituted benzene-linked thiazolidinedione analogs by coupling reaction of the hydrophobic segments with hydroxybenzylthiazolidinedione.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1636-1642
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• 2016

Phenalamide is a bioactive secondary metabolite produced by Myxococcus stipitatus. We identified a 56 kb phenalamide biosynthetic gene cluster from M. stipitatus DSM 14675 by genomic sequence analysis and mutational analysis. The cluster is comprised of 12 genes (MYSTI_04318- MYSTI_04329) encoding three pyruvate dehydrogenase subunits, eight polyketide synthase modules, a non-ribosomal peptide synthase module, a hypothetical protein, and a putative flavin adenine dinucleotide-binding protein. Disruption of the MYSTI_04324 or MYSTI_04325 genes by plasmid insertion resulted in a defect in phenalamide production. The organization of the phenalamide biosynthetic modules encoded by the fifth to tenth genes (MYSTI_04320-MYSTI_04325) was very similar to that of the myxalamid biosynthetic gene cluster from Stigmatella aurantiaca Sg a15, as expected from similar backbone structures of the two substances. However, the loading module and the first extension module of the phenalamide synthase encoded by the first to fourth genes (MYSTI_04326-MYSTI_04329) were found only in the phenalamide biosynthetic gene cluster from M. stipitatus DSM 14675.

• Natural Product Sciences
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• 제21권4호
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• pp.282-288
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• 2015

Viriditoxin is a fungal metabolite isolated from Paecilomyces variotii, which was derived from the giant jellyfish Nemopilema nomurai. Viriditoxin was reported to inhibit polymerization of FtsZ, which is a key protein for bacterial cell division and a structural homologue of eukaryotic tubulin. Both tubulin and FtsZ contain a GTP-binding domain, have GTPase activity, assemble into protofilaments, two-dimensional sheets, and protofilament rings, and share substantial structural identities. Accordingly, we hypothesized that viriditoxin may inhibit eukaryotic cell division by inhibiting tubulin polymerization as in the case of bacterial FtsZ inhibition. Docking simulation of viriditoxin to ${\beta}-tubulin$ indicated that it binds to the paclitaxel-binding domain and makes hydrogen bonds with Thr276 and Gly370 in the same manner as paclitaxel. Viriditoxin suppressed growth of A549 human lung cancer cells, and inhibited cell division with G2/M cell cycle arrest, leading to apoptotic cell death.