• Title/Summary/Keyword: Membrane binding

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Induction of Immune Responses by Two Recombinant Proteins of Brucella abortus, Outer Membrane Proteins 2b Porin and Cu/Zn Superoxide Dismutase, in Mouse Model

  • Sung, Kyung Yong;Jung, Myunghwan;Shin, Min-Kyoung;Park, Hyun-Eui;Lee, Jin Ju;Kim, Suk;Yoo, Han Sang
    • Journal of Microbiology and Biotechnology
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    • v.24 no.6
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    • pp.854-861
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    • 2014
  • The diagnosis of Brucella abortus is mainly based on serological methods using antibody against LPS, which has diagnostic problems. Therefore, to solve this problem, we evaluated two proteins of B. abortus, Cu/Zn superoxide dismutase (SodC) and outer membrane proteins 2b porin (Omp2b). The genes were cloned and expressed in a pMAL system, and the recombinant proteins, rOmp2b and rSodC, were purified as fusion forms with maltose-binding protein. The identity of the proteins was confirmed by SDS-PAGE and Western blot analysis with sera of mice infected with B. abortus. Production of cytokines and nitric oxide (NO) was investigated in RAW 264.7 cells and mouse splenocytes after stimulation with the proteins. Moreover, cellular and humoral immune responses were investigated in BALB/c mice after immunization with the proteins. TNF-${\alpha}$, IL-6, and NO were significantly inducible in RAW 264.7 cells. Splenocytes of naive mice produced IFN-${\gamma}$ and IL-4 significantly by stimulation. Moreover, number of IgG, IFN-${\gamma}$, and IL-4 producing cells were increased in immunized mice with the two proteins. Production of IgG and IgM with rOmp2b was higher than those with rSodC in immunized mice. These results suggest that the two recombinant proteins of B. abortus may be potential LPS-free proteins for diagnosis.

Structure and Bacterial Cell Selectivity of a Fish-Derived Antimicrobial Peptide, Pleurocidin

  • Yang Ji-Young;Shin Song-Yub;Lim Shin-Saeng;Hahm Kyung-Soo;Kim Yang-Mee
    • Journal of Microbiology and Biotechnology
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    • v.16 no.6
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    • pp.880-888
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    • 2006
  • Pleurocidin, an $\alpha$-helical cationic antimicrobial peptide, was isolated from skin mucosa of winter flounder (Pleuronectes americamus). It had strong antimicrobial activities against Gram-positive and Gram-negative bacteria, but had very weak hemolytic activity. The Gly$^{13,17}\rightarrow$Ala analog (pleurocidin-AA) showed similar antibacterial activities, but had dramatically increased hemolytic activity. The bacterial cell selectivity of pleurocidin was confirmed through the membrane-disrupting and membrane-binding affinities using dye leakage, tryptophan fluorescence blue shift, and tryptophan quenching experiments. However, the non-cell-selective antimicrobial peptide, pleurocidin-AA, interacts strongly with both negatively charged and zwitterionic phospholipid membranes, the latter of which are the major constituents of the outer leaflet of erythrocytes. Circular dihroism spectra showed that pleurocidin-AA has much higher contents of $\alpha$-helical conformation than pleurocidin. The tertiary structure determined by NMR spectroscopy showed that pleurocidin has a flexible. structure between the long helix from $Gly^3$ to $Gly^{17}$ and the short helix from $Gly^{17}$ to $Leu^{25}$. Cell-selective antimicrobial peptide pleurocidin interacts strongly with negatively charged phospholipid membranes, which mimic bacterial membranes. Structural flexibility between the two helices may play a key role in bacterial cell selectivity of pleurocidin.

Immune Modulation of Recombinant OmpA against Brucella abortus 544 Infection in Mice

  • Simborio, Hannah Leah Tadeja;Reyes, Alisha Wehdnesday Bernardo;Hop, Huynh Tan;Arayan, Lauren Togonon;Min, Wongi;Lee, Hu Jang;Lee, Jin Ju;Chang, Hong Hee;Kim, Suk
    • Journal of Microbiology and Biotechnology
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    • v.26 no.3
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    • pp.603-609
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    • 2016
  • Brucellosis affects a wide range of host species, including humans and many livestock animals. Chronic infections of the disease make antibiotic treatment costly, and the current vaccine used in livestock has not been approved for human use. This study investigated the possible use of the Brucella abortus outer membrane protein A (OmpA) as a candidate subunit vaccine in an infected mouse model. The ompA gene was cloned and overexpressed, and the recombinant OmpA (rOmpA) protein fused to maltose binding protein (MBP) was purified in Escherichia coli. Immunogenicity was verified through western blotting, and mice were immunized and challenged to evaluate its protective effect. Mice treated with rOmpA exhibited induced humoral and host cell-mediated responses, with a significant increase in immunoglobulin G (IgG1 and IgG2a) and cytokine levels, especially TNF-α and IL-12, compared with the control groups treated with either MBP or PBS. In conclusion, rOmpA should be highly considered as a future subunit vaccine for brucellosis, and further studies regarding rOmpA and its protective ability are suggested.

Functional characterizations of residues Arg-158 and Tyr-170 of the mosquito-larvicidal Bacillus thuringiensis Cry4Ba

  • Leetachewa, Somphob;Moonsom, Saengduen;Chaisri, Urai;Khomkhum, Narumol;Yoonim, Nonglak;Wang, Ping;Angsuthanasombat, Chanan
    • BMB Reports
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    • v.47 no.10
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    • pp.546-551
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    • 2014
  • The insecticidal activity of Bacillus thuringiensis (Bt) Cry toxins involves toxin stabilization, oligomerization, passage across the peritrophic membrane (PM), binding to midgut receptors and pore-formation. The residues Arg-158 and Tyr-170 have been shown to be crucial for the toxicity of Bt Cry4Ba. We characterized the biological function of these residues. In mosquito larvae, the mutants R158A/E/Q (R158) could hardly penetrate the PM due to a significantly reduced ability to alter PM permeability; the mutant Y170A, however, could pass through the PM, but degraded in the space between the PM and the midgut epithelium. Further characterization by oligomerization demonstrated that Arg-158 mutants failed to form correctly sized high-molecular weight oligomers. This is the first report that Arg-158 plays a role in the formation of Cry4Ba oligomers, which are essential for toxin passage across the PM. Tyr-170, meanwhile, is involved in toxin stabilization in the toxic mechanism of Cry4Ba in mosquito larvae.

The efficiency of topical anesthetics as antimicrobial agents: A review of use in dentistry

  • Kaewjiaranai, Thanawat;Srisatjaluk, Ratchapin Laovanitch;Sakdajeyont, Watus;Pairuchvej, Verasak;Wongsirichat, Natthamet
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.18 no.4
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    • pp.223-233
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    • 2018
  • Topical anesthetics are commonly used in oral & maxillofacial surgery to control pain in the oral cavity mucosa before local anesthetic injection. These anesthetic agents come in many forms, developed for different usages, to minimize adverse reactions, and for optimal anesthetic efficiency. Earlier studies have revealed that these agents may also limit the growth of microorganisms in the area of anesthetic application. Many topical anesthetic agents show different levels of antimicrobial activity against various bacterial strains and Candida. The dosage of local anesthetic agent used in some clinical preparations is too low to show a significant effect on microbial activity. Efficiency of antimicrobial activity depends on the local anesthetic agent's properties of diffusion within the bloodstream and binding efficiency with cytoplasmic membrane, which is followed by disruption of the bacterial cell membrane. The antimicrobial properties of these agents may extend their usage in patients to both control pain and infection. To develop the topical local anesthetic optimal usage and antimicrobial effect, a collaborating antiseptic agent may be used to benefit the local anesthetic. However, more research is required regarding minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of topical local anesthetic agents with drug interaction between anesthetics and antiseptic agents.

Effect of L-carnitine on sperm quality during liquid storage of boar semen

  • Yang, Kang;Wang, Na;Guo, Hai-Tao;Wang, Jing-Ran;Sun, Huan-Huan;Sun, Liang-Zhen;Yue, Shun-Li;Zhou, Jia-Bo
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.11
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    • pp.1763-1769
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    • 2020
  • Objective: This study was conducted to investigate the effect of L-carnitine on the pig semen characteristics during storage. Methods: Spermatozoa samples were examined for spermatozoa quality and then randomly divided into 5 groups: 0 (control), 12.5, 25, 50, and 100 mM L-carnitine. Sperm motility, plasma membrane integrity and antioxidant parameters (total reactive oxygen species, total antioxidant capacity, and malondialdehyde) were evaluated after 0, 3, 5, and 10 day cooled-storage at 17℃. Moreover, ATP content, mitochondria activity as well as sperm-binding and in vitro fertilizing ability of preserved boar sperm were also investigated. Results: Supplementation with 50 mM L-carnitine could effectively maintain boar sperm quality parameters such as sperm motility and membrane integrity. Besides, we found that L-carnitine had positive effects on boar sperm quality mainly through improving antioxidant capacities and enhancing ATP content and mitochondria activity. Interestingly, by assessing the effect of L-carnitine on sperm fertility and developmental potential, we discovered that the extender containing L-carnitine could improve sperm quality and increase the number of sperms bounding to zona pellucida, without improving in vitro fertility and development potential. Conclusion: These findings suggested that the proper addition of L-carnitine to the semen extender improved boar sperm quality during liquid storage at 17℃.

The Experimental Study about Antioxidant Activities of Alismatis Rhizoma Herbal Acupuncture (택사약침(澤瀉藥鍼)의 항산화효과(抗酸化效果)에 관(關)한 실험적(實驗的) 연구(硏究))

  • Lee, Jong-moo;Lee, Byung-ryul
    • Journal of Acupuncture Research
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    • v.20 no.1
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    • pp.159-176
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    • 2003
  • Objective : The purpose of this study is to investigate the antioxidant activities of Alismatis Rhizoma herbal acupuncture by experimental methods. Methods : For this purpose, first, we put an emphasis in the control of enzymes of the antioxidant system in various changes inside the cell; these changes caused by the proliferation or the activation of the cell which were brought about by the handling of PMA and $TNF-{\alpha}$ into the THP-1 monocyte cell of the body each other. After that, we caused the acute oxidant symptom by the injection of AAPH into the mouse' abdominal cavity, and then applied the herbal acupuncture on S36 point(足三里), and finally, we measured the change of blood ingredient and the resistance against the activated oxygen of the red blood cell membrane, MDA, SOD, and catalase. Results : In vitro the revelation of $IL-1{\beta}$, IL-8, $TNF-{\alpha}$, NOS II and IL-6 were decreased and the revelation of IL-10, $TGF-{\beta}$, GM-CSFIL-12, GM-CSF and SOD were increased. The DNA-binding of $NF-{\kappa}B$ and AP-1 were activated and the formation of ROS in the THP-1 cell line was decreased. In vivo $IL-1{\beta}$ among producing the cytokine inside the plasma was meaningfully dwindled and the $INF-{\gamma}$ was meaningfully increased. The resistance of red blood cell membrane against the activated oxygen was meaningfully increased and the MDA formation was meaningfully dwindled, In the activation of hepatic antioxidase, the SOD was meaningfully increased. Conclusion : Alismatis Rhizoma herbal acupuncture by experimental methods has effected on the antioxidant activities.

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Characteristics of Lead Accumulation in Lead-Tolerant Pseudomonas aeruginosa (납 내성균의 균체내 납 축적 특성)

  • Cho, Ju-Sik;Lee, Hong-Jae;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.15 no.3
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    • pp.306-315
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    • 1996
  • This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. The lead-tolerant microorganism, Pseudomonas aeruginosa which possessed the ability to accumulate lead, was isolated from the industrial wastewater polluted with various heavy metals. The characteristics of lead accumulation in the cells and the recovery of the lead there from were investigated. Removal rate of lead from the solution containing 100mg/l of lead by the lead-tolerant microorganism was more than 97% at 48 hours after inoculation with the microorganism. A large number of the electron-dense granules were found mainly on the cell wall and cell membrane fractions, when determined by transmission electron microscopy. Energy dispersive X-ray spectroscopy revealed that the electron-dense granules were lead complex with the substances binding heavy metals. The lead accumulated into cells was not desorbed by distilled water, but more than 87% of the lead accumulated was desorbed by 0.1M-EDTA. The residues of the cells after combustion at $550^{\circ}C$ amounted to about 30% of the dry weight of the cells. EDS analysis showed that the residues were relatively pure lead compounds containing more than 86% of lead.

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Effect of Ethanol on $Na^+-P_i$ Uptake in Opossum Kidney Cells: Role of Membrane Fluidization and Reactive Oxygen Species

  • Park, In-Ho;Hwang, Moon-Young;Woo, Jae-Suk;Jung, Jin-Sup;Kim, Yong-Keun
    • The Korean Journal of Physiology and Pharmacology
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    • v.3 no.5
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    • pp.529-538
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    • 1999
  • This study was undertaken to examine the effect of ethanol on $Na^+ -dependent$ phosphate $(Na^+-P_i)$ uptake in opossum kidney (OK) cells, an established renal proximal tubular cell line. Ethanol inhibited ^Na^+-dependent$ component of phosphate uptake in a dose-dependent manner with $I_{50}$ of 8.4%, but it did not affect $Na^+-independent$ component. Similarly, ethanol inhibited $Na^+-dependent$ uptakes of glucose and amino acids (AIB, glycine, alanine, and leucine). Microsomal $Na^+-K^+-ATPase$ activity was not significantly altered when cells were treated with 8% ethanol. Kinetic analysis showed that ethanol increased $K_m$ without a change in $V_{max}$ of $Na^+-P_i$ uptake. Inhibitory effect of n-alcohols on $Na^+-P_i$ uptake was dependent on the length of the hydrocarbon chain, and it resulted from the binding of one molecule of alcohol, as indicated by the Hill coefficient (n) of 0.8-1.04. Catalase significantly prevented the inhibition, but superoxide dismutase and hydroxyl radical scavengers did not alter the ethanol effect. A potent antioxidant DPPD and iron chelators did not prevent the inhibition. Pyrazole, an inhibitor of alcohol dehydrogenase, did not attenuate ethanol-induced inhibition of $Na^+-P_i$ uptake, but it prevented ethanol-induced cell death. These results suggest that ethanol may inhibit $Na^+-P_i$ uptake through a direct action on the carrier protein, although the transport system is affected by alterations in the lipid environment of the membrane.

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A WD40 Repeat Protein, Arabidopsis Sec13 Homolog 1, May Play a Role in Vacuolar Trafficking by Controlling the Membrane Association of AtDRP2A

  • Lee, Myoung Hui;Lee, Sung Hoon;Kim, Heyran;Jin, Jing Bo;Kim, Dae Heon;Hwang, Inhwan
    • Molecules and Cells
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    • v.22 no.2
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    • pp.210-219
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    • 2006
  • Dynamin-related protein 2A (AtDRP2A, formally ADL6), a member of the dynamin family, is critical for protein trafficking from the TGN to the central vacuole. However, the mechanism controlling its activity is not well understood in plant cells. We isolated Arabidopsis sec13 homolog1 (AtSeh1) that interacts with AtDRP2A by a yeast two-hybrid screening. AtSeh1 has four WD40 motifs and amino acid sequence homology to Sec13, a component of COPII vesicles. Coimmunoprecipitation and protein pull-down experiments demonstrated specific interaction between AtSeh1 and AtDRP2A. AtSeh1 bound to the pleckstrin homology domain of AtDRP2A in competition with the C-terminal domain of the latter, and this resulted in inhibition of the interaction between AtDRP2A and PtdIns3P in vitro. AtSeh1 localized to multiple locations: the nucleus, the prevacuolar compartment and the Golgi complex. Based on these results we propose that AtSeh1 plays a role in regulating cycling of AtDRP2A between membrane-bound and soluble forms.