• 제목/요약/키워드: Outer membrane protein

검색결과 150건 처리시간 0.028초

Identification of Inhibitors Against BAK Pore Formation using an Improved in vitro Assay System

  • Song, Seong-Soo;Lee, Won-Kyu;Aluvila, Sreevidya;Oh, Kyoung Joon;Yu, Yeon Gyu
    • Bulletin of the Korean Chemical Society
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    • 제35권2호
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    • pp.419-424
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    • 2014
  • The pro-apoptotic BCL-2 family protein BID activates BAK and/or BAX, which form oligomeric pores in the mitochondrial outer membrane. This results in the release of cytochrome c into the cytoplasm, initiating the apoptotic cascade. Here, we utilized liposomes encapsulating sulfo-rhodamine at a controlled temperature to improve upon a previously reported assay system with enhanced sensitivity and specificity for measuring membrane permeabilization by BID-dependent BAK activation. BAK activation was inhibited by BCL-$X_L$ protein but not by a mutant protein with impaired anti-apoptotic activity. With the assay system, we screened a chemical library and identified several compounds including trifluoperazine, a mitochondrial apoptosis-induced channel blocker. It inhibited BAK activation by direct binding to BAK and blocking the oligomerization of BAK.

세포고사의 핵의학영상 (In Vivo Nuclear Imaging of Apoptosis)

  • 이태섭;천기정
    • 대한핵의학회지
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    • 제38권2호
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    • pp.190-197
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    • 2004
  • Apoptosis plays a role in the pathophysiology of many kinds of diseases and in the response of treatment. Compared to the necrosis, the apoptosis is a genetically controlled and energy-dependent process which removes the unwanted cells from the body; programmed cell death or cell suicide. During the apoptosis, phosphatidylserine is expressed in the cytoplasmic outer membrane in the early phase. Annexin V, an endogenous human protein (MW=35 kD), has an affinity of about $10^{-9}\;M$ for the phosphatidylserine exposed on the outer membrane of apoptotic cells. Annexin V can be radiolabeled with $^{99m}Tc$ by HYNIC or EC chelators, which can be used as an radiotracer for the in vivo imaging of apoptosis. In this article, we reviewed the apoptosis, radiolabeling of annexin V, and the experimental and clinical data using annexin V imaging.

Understanding of Interactions Between Acanthamoeba and Escherichia coli on Cell-Based System

  • Jung, Suk-Yul
    • 대한의생명과학회지
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    • 제17권3호
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    • pp.173-176
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    • 2011
  • Free-living Acanthamoeba are eukaryotic protozoan organisms that are widely distributed in the air, water, etc such as environment. Acanthamoeba ingest the Escherichia coli which will replicate in cytoplasm of Acanthamoeba. Bacterial pathogenicity or virulence is one of important determinant factors to survive in free-living Acanthamoeba and otherwise Acanthamoebic pathogenicity is also an important factor for their interactions. Bacterial association with pathogenic strain of Acanthamoeba T1 and T4 was lower about two times than non-pathogenic T7. Bacterial invasion percentages into T1 were higher about three times than T7 but bacterial survival in T7 was increased as T1. The capsule-deletion mutant exhibited limited ability for invasion/uptake by and survival inside pathogenic Acanthamoeba T4. E. coli-outer membrane protein A (OmpA) decreased bacterial association with A. castellanii by about three times and it had higher effects than lipopolysaccharides (LPS). Under favorable conditions, the mutants were not survived in Acanthamoeba up to 24 h incubation. Therefore, this review will report pathogenic and non-pathogenic Acanthamoeba strains interactions with E. coli and its several mutants, i.e., capsule, OmpA and LPS.

Characterization of the Salmonella typhi Outer Membrane Protein C

  • Toobak, Hoda;Rasooli, Iraj;Gargari, Seyed Latif Mousavi;Jahangiri, Abolfazl;Nadoushan, Mohammadreza Jalali;Owlia, Parviz;Astaneh, Shakiba Darvish Alipour
    • 한국미생물·생명공학회지
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    • 제41권1호
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    • pp.128-134
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    • 2013
  • Salmonella enterica serovar typhi, a Gram-negative food-borne pathogen, causes typhoid fever in humans. OmpC is an outer membrane porin of S. typhi expressed throughout the infection period. OmpC is potentially an attractive antigen for multivalent vaccines and diagnostic kit designs. In this study we combined in silico, in vitro and in vivo approaches to analyze various aspects of OmpC's antigenic properties. The conserved region, in addition to secondary and tertiary structures, and linear B cell epitopes, were predicted. A number of results obtained from in silico analyses were validated by experimental studies. OmpC was amplified, cloned and then expressed, with the recombinant protein then being purified. BALB/c mice were immunized by purified denatured OmpC. The titer of antibody was raised. Results of challenges with the pathogen revealed that the immunity is non-protective. Most of the theoretical and experimental results were in consensus. Introduced linear B cell epitopes can be employed for the design of diagnostic kits based on antigen-antibody interactions.

살모넬라 세포외막단백질 혼합백신을 이용한 돼지 및 닭에서의 살모넬라균감염증 방어효과 (Protective effects of mix-crude outer membrane protein Salmonella vaccine against salmonellosis in chickens and pigs)

  • 이희수;임숙경;조윤상;주이석;김재학;김종만
    • 대한수의학회지
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    • 제47권2호
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    • pp.147-155
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    • 2007
  • We investigated the safety, immunogenicity and protectivity of mix-crude outer membrane protein (cOMP) vaccine against salmonellosis in animals. The mix-cOMP vaccine was extracted from Salmonella enterica serovar Typhimurium (ST) and Salmonella enterica serovar Enteritidis (SE) and Salmonella enterica serovar Braenderup (SB) isolated from pigs. The mix-cOMP vaccine gave significantly higher antibody response than ST-bacterin and ST-cOMP vaccine in guinea pigs. The survival rates of mix-cOMP vaccinated groups showed significantly higher (100%) than those (0-20%) of unvaccinated control group, challenged with 3 species of Salmonella (ST, SE and SB) in mice. Vaccinated groups in pigs showed reduction of clinical signs, increase of average weight gains, decrease of bacterial recovery rates, compared with unvaccinated groups. Especially, the survival rates (100%) of vaccinated groups in chickens showed higher than that (0%) of unvaccinated group. Based on these results, we suggest that the mix-cOMP Salmonella vaccine developed in this study will be effective for the protection against Salmonellosis caused by the various serotypes Salmonella species in animals.

Surface interactions between two of the main periodontal pathogens: Porphyromonas gingivalis and Tannerella forsythia

  • Zhu, Weidong;Lee, Seok-Woo
    • Journal of Periodontal and Implant Science
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    • 제46권1호
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    • pp.2-9
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    • 2016
  • Purpose: Porphyromonas gingivalis and Tannerella forsythia have been implicated as the major etiologic agents of periodontal disease. These two bacteria are frequently isolated together from the periodontal lesion, and it has been suggested that their interaction may increase each one's virulence potential. The purpose of this study was to identify proteins on the surface of these organisms that are involved in interbacterial binding. Methods: Biotin labeling of surface proteins of P. gingivalis and T. forsythia and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was performed to identify surface proteins involved in the coaggregating activity between P. gingivalis and T. forsythia. Results: It was found that three major T. forsythia proteins sized 161, 100, and 62 kDa were involved in binding to P. gingivalis, and P. gingivalis proteins sized 35, 32, and 26 kDa were involved in binding to T. forsythia cells. Conclusions: LC-MS/MS analysis identified one T. forsythia surface protein (TonB-linked outer membrane protein) involved in interbacterial binding to P. gingivalis. However, the nature of other T. forsythia and P. gingivalis surface proteins identified by biotin labeling could not be determined. Further analysis of these proteins will help elucidate the molecular mechanisms that mediate coaggregation between P. gingivalis and T. forsythia.

CFC-101(녹농균 백신)의 능동 및 수동면역 효과 (Active and Passive Protective Effect of CFC-101 (Pseudomonas Vaccine) in Mice)

  • 박완제;조양제;김영지;김제학;박관하;김유삼;함경수
    • Biomolecules & Therapeutics
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    • 제2권4호
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    • pp.326-330
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    • 1994
  • The treatment of pseudomonal infection is a perplexed problem because of its modest susceptibility to most of the major antibiotics. A novel Pseudomonas vaccine(CFC-101) was prepared from the outer membrane protein fractions of several Pseudomonas strains. In this study, we examined CFC-101's effectiveness in both active and passive immunization models. CFC-101 in mice at 0.2 mg/kg, i.p., given three times at two-day intervals, completely prevented the death caused by Pseudomonas aeruginosa. Antibody titer, in accordance with the protective effect in this active immunization, was elevated to its peak level following three consecutive administrations of CFC-101. Thereafter, antibody titer stayed at a constantly high level. Each outer membrane protein fraction from the four CFC-101 producers, exhibited good cross-protective effects in mouse infection models against different Fisher types of P. aeruginosa. In the passive immunization model, 21~336 $\mu\textrm{g}$/kg of anti-rabbit IgG to CFC-101, when mice being infected with a challenge strain, prevented the Pseudomonhas-induced death up to 60%. Therefore, the preventive effect of CFC-101 was verified in both the active and passive immunization models.

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Atomic Force Microscopy of Asymmetric Membranes from Turtle Erythrocytes

  • Tian, Yongmei;Cai, Mingjun;Xu, Haijiao;Ding, Bohua;Hao, Xian;Jiang, Junguang;Sun, Yingchun;Wang, Hongda
    • Molecules and Cells
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    • 제37권8호
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    • pp.592-597
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    • 2014
  • The cell membrane provides critical cellular functions that rely on its elaborate structure and organization. The structure of turtle membranes is an important part of an ongoing study of erythrocyte membranes. Using a combination of atomic force microscopy and single-molecule force spectroscopy, we characterized the turtle erythrocyte membrane structure with molecular resolution in a quasi-native state. High-resolution images both leaflets of turtle erythrocyte membranes revealed a smooth outer membrane leaflet and a protein covered inner membrane leaflet. This asymmetry was verified by single-molecule force spectroscopy, which detects numerous exposed amino groups of membrane proteins in the inner membrane leaflet but much fewer in the outer leaflet. The asymmetric membrane structure of turtle erythrocytes is consistent with the semi-mosaic model of human, chicken and fish erythrocyte membrane structure, making the semi-mosaic model more widely applicable. From the perspective of biological evolution, this result may support the universality of the semi-mosaic model.