• 제목/요약/키워드: toxic proteins

검색결과 151건 처리시간 0.028초

Toxic Effects of Catechol and 4-Chlorobenzoate Stresses on Bacterial Cells

  • Park, Sang-Ho;Ko, Yeon-Ja;Kim, Chi-Kyung
    • Journal of Microbiology
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    • 제39권3호
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    • pp.206-212
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    • 2001
  • Catechol and 4-chlorobenzoate (4CBA) which are produced from the biodegradation of a variety of aromatic and chloroaromatics have been recognized as toxic to living organisms. In this study, the toxic effects of catechol and 4-chlorobenzoate on gram-positive and -negative bacteria were examined in terms of survival, morphology, change in fatty acids and membrane protein composition. The survival rate of the organisms during treatment for 6 h was decreased, as the concentration of each aromatic was increased. Escherichia coli and Pseudomonas cells treated with catechol and 4CBA at concentrations causing a significant decrease in their viability, showed destructive openings in their cell envelopes. Bacills subtilis treated with the aromatics were reduced in cell size and Staphylococcus aureus cells displayed irregular rod shapes with wrinkled surfaces. The bacterial cells treated with 20 mM catechol showed increases in unsaturated fatty acids, but several saturated fatty acids were decreased. In the E. coli cells treated with 20 mM catechol, inner membrane proteins of 150 kDa and 105 kDa were decreased. But several kinds of the inner and outer membrane proteins were increased. In B. subtilis treated with 20 mM catechol, several kinds of proteins were increased or decreased in membrane proteins.

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인간 퓨린수용체 $P2X_4$를 발현시킬 때 나타나는 대장균 독성의 원인분석 (Analysis of Toxicity in Escherichia coli from the Expression of Human Purinergic Receptor $P2X_4$)

  • 유연주;정윤아;임동빈
    • 미생물학회지
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    • 제47권1호
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    • pp.7-13
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    • 2011
  • 일반적으로 대장균을 숙주로 이용하여 고등생물 유래 막단백질을 발현시킬 경우 발현된 막단백질은 숙주 세포에 치명적인 독성을 보인다. 우리가 발현을 시도한 15개의 인간 막단백질 중에서 특히 퓨린수용체 $P2X_4$ 발현은 대장균에 강한 독성을 보였다. 이러한 독성의 원인을 알아보기 위해 hydroxylamine을 사용하여 하여 인간 $P2X_4$ 유전자를 돌연변이 시키고 독성이 약해진 돌연변이체를 선별하였다. 돌연변이체 단백질을 면역블랏으로 분석한 결과 야생형에 비해 모두 단백질의 크기가 작았다. 크기가 제법 큰 돌연변이 두 개를 골라 DNA 서열분석을 해보니 130번째, 또는 194번째 Trp 코돈이 종결코돈으로 바뀜으로써 두 번째 막통과 도메인이 사라진 truncated protein이라는 사실을 알았다. 이들 돌연변이체의 세포내 위치를 추적해보니 둘 다 세포막에 삽입되어 있지는 않았다. 이런 결과를 종합해 볼 때 $P2X_4$의 발현이 대장균에 독성을 보이기 위해서는 전체 단백질의 올바른 세포막 삽입이 중요함을 시사한다.

TOXIC EFFECTS OF 2,4-D AND OTHER AROMATIC COMPOUNDS ON BACTERIA, AND THEIR PROTECTIVE RESPONSES

  • Oh, Kye-Heon;Kim, Chi-Kyung
    • 한국미생물생명공학회:학술대회논문집
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    • 한국미생물생명공학회 2000년도 Proceedings of 2000 KSAM International Symposium and Spring Meeting
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    • pp.116-123
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    • 2000
  • The purpose of this work was to investigate the induction of stress shock proteins (SSPs) in Burkholderia sp. YK-2 in response to 2,4-dichlorophenoxyacetic acid (2,4-D), and Pseudomonas sp. DJ-12 to benzoate, 4-chlorobenzoate (4-CBA), 4-hydroxybenzoate, and biphenyl. The SSPs, which contribute to the resistance of the cytotoxic effect of the toxic aromatic compounds including 2,4-D and 4-CBA, were induced at different concentrations of the compounds in exponentially growing cultures of Burkholderia sp. YK-2 or Pseudomonas sp. DJ-12. This response involved the induction of a 43 kDa DnaK and 41 kDa GroEL proteins in Burkholderia sp. YK-2, characterized by SDS-PAGE and Western blot using the anti-DnaK and anti-GroEL monoclonal antibodies. In Pseudomonas sp. DJ-12, 70 kDa DnaK and 60 kDa GroEL proteins was induced as SSPs, respectively. The total SSPs were analyzed by 2-D PAGE. Survival of Burkholderia sp. YK-2 or Pseudomonas sp. DJ-12 with time in the presence of different concentrations of the compounds was monitored, and viable counts paralleled the induction of the SSPs in these strains. Cells treated with the increased concentrations of toxic compounds showed some destructive openings on the cell envelopes.

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Immuno-Affinity Chromatography에 의한 B. thuringiensis H9B 균주의 모기살충성 내독소 단백질의 정제 (Purification of a Mosquitocidal Toxic Protein from B. thuringiensis strain H9B by Immuno-Affinity Chromatography)

  • 김광현;배수장;이광배
    • 환경위생공학
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    • 제12권2호
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    • pp.59-64
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    • 1997
  • For purification of a 70kDa toxic protein of mosquitocidal delta-endotoxin from B. thuringiensis strain H9B, immuno-affinity chromatography was performed. After separation of 70kDa toxic proteins from the delta-endotoxin of the strain H9B on SDS-PAGE, the 70kDa toxic protein was subcutaneously injected into rabbit for making a polyclonal antibody. A anti-70kDa toxic protein was purified by a column chromatography packed with protein A-sepharose 4B gels. The 70kDa toxic protein from delta-endotoxin of the strain H9B was also purified by an immuno-affinity chromatography packed with CNBr-activated sepharose 4B gels conjugated anti-70kDa toxic protein after elution with 1/10M citric acid-1/5M Na$_{2}$HPO$_{4}$ buffer(pH3.2) containing 0.5M NaCl. The 70kDa toxic protein was purified through only one step-separation system, was demonstrated by SDS-PAGE and immunoblot.

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PEG 접합: 단백질 및 펩타이드 치료제의 약효를 증가시키는 새로운 기술 (PEGYLATION: Novel Technology to Enhance Therapeutic Efficacy of Proteins and Peptides)

  • 박명옥;이강춘
    • Journal of Pharmaceutical Investigation
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    • 제30권2호
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    • pp.73-83
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    • 2000
  • Polyethylene glycol (PEG) is a water soluble, biocompatible, non-toxic polymer and PEGylation is a well established technique for the modification of therapeutic proteins and peptides. PEG-protein drugs have been extensively studies in relation to therapies for various diseases: cancer, inflammation and others. The covalent attachment of PEG to proteins and peptides prolonged plasma half-life, reduced antigenicity and immunogenicity, increased thermal and mechanical stability, and prevented degradation by enzymes. Several chemical groups for general and site specific conjugation have been exploited to activate PEG for amino group, carboxyl group, and cysteine groups. PEGylation of many proteins and peptides have been studied to enhance their properties for the potential uses. Also, the different positional isomers in several PEG-proteins have shown the difference in vivo stability and biological indicating that the site of PEG molecule attachment is one of the important factor to develop PEG-proteins as potential therapeutic agents.

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Comparative Study of Processed (Shodhit) and Unprocessed Seeds of 'Gunja'-Abrus precatorius L.

  • Gautam, D.N. Singh;Singh, P.N.;Mehrotra, Shanta
    • Natural Product Sciences
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    • 제5권3호
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    • pp.127-133
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    • 1999
  • 'Gunja' is attributable to the plant Abrus precatorius L. (Leguminosae). Three forms with red, brown and another with white seeds are known to occur in this species and are employed for different therapeutic uses viz. as purgative, emetic, aphrodisiac, tonic and also as an abortifacient. According to some Ayurvedic literature the seeds are poisonous and should be given to the patients after proper processing ('Shodhan'). A comparative study of various phytochemical parameters, namely, percentage of successive extractives, total proteins, tannins, total ash and acid insoluble ash of these three forms of the processed (with cow's milk and Kanji) and unprocessed seeds was done. TLC and densitometric scanning of successive extractives was also carried out to serve as markers for processed and unprocessed seeds. The percentage of proteins, tannins, alcohol and water soluble extractives decreased in the processed material. Besides, their acute toxicity, CNS activity were also studied in albino mice and it was found that white seeds are more toxic as compared to the red and brown. The toxic effect was reduced with the processing. Further, the 'Kanji' processed seeds are less toxic than the milk processed one.

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몇 가지 PBTs (Persistent, Bioaccumulative, Toxic Chemicals)가 생태계 곤충에 미치는 영향

  • 이선영;김용균
    • 한국환경생물학회:학술대회논문집
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    • 한국환경생물학회 2002년도 학술대회
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    • pp.123-126
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    • 2002
  • Pollutants that are persistent, bioaccurnulative, and toxic have been linked to numerous adverse effects in human and animals, PBTs include heavy metals, polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic compounds (PACs) in addition to pesticides. This study focuses on toxic effects of the PBTs except pesticides on insects. Eight PBTs were selected from subgroups: three heavy metals (Pb, Hg, and Cd), two PCB mixtures (Aroclor mixtures 1 and 2), 2,3,7,8-tetrachlorodibenzo-p-dioxin, two monophenols (4-octylphenol and 4-nonylphenol), and tetrabutyltin, Beet armyworm, Spodoptera exigua, was used as test target insect species. Three physiological markers (metamorphosis, immune reaction, and follicle patency) were assessed in each exposure to different doses of the PCBs. Heat-shock proteins as molecular markers were also analyzed in response to the PCBs. All tested PBTs were toxic to metamorphosis from larvae to pupae when they were applied with diet. Two PCB mixtures were the most toxic compounds in this assay by giving significant toxicity at 0.005 ppm, while others had from 10 to 1000 ppm. Dioxin (0.1 ppb), tetrabutyltin (0.1 ppb), Pb (10 ppb), and Hg (0,01 ppb) were potent to inhibit immune reactions analyzed by inducing phenoloxidase activity and blocked phospholipase $A_2$ enzyme, Tetrabutyltin and dioxin significantly induced follicle cell patency, but their effects were lower than that of endogenous juvenile hormone, Dioxin, Pb, Hg, and Cd could induce the expression of heat shock proteins that were detected by immunoblotting against human HSP70 monoclonal antibody. HSP78 and HSP80 were upregulated in response to the PBTs. This expression was detected from the fat body and epidermis at as fast as 4h after injection. All these results clearly suggest that PBTs give significant ecotoxicity to insects that are valuable organisms in our environment.

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Therapeutic implication of autophagy in neurodegenerative diseases

  • Rahman, Md. Ataur;Rhim, Hyewhon
    • BMB Reports
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    • 제50권7호
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    • pp.345-354
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    • 2017
  • Autophagy, a catabolic process necessary for the maintenance of intracellular homeostasis, has recently been the focus of numerous human diseases and conditions, such as aging, cancer, development, immunity, longevity, and neurodegeneration. However, the continued presence of autophagy is essential for cell survival and dysfunctional autophagy is thought to speed up the progression of neurodegeneration. The actual molecular mechanism behind the progression of dysfunctional autophagy is not yet fully understood. Emerging evidence suggests that basal autophagy is necessary for the removal of misfolded, aggregated proteins and damaged cellular organelles through lysosomal mediated degradation. Physiologically, neurodegenerative disorders are related to the accumulation of amyloid ${\beta}$ peptide and ${\alpha}-synuclein$ protein aggregation, as seen in patients with Alzheimer's disease and Parkinson's disease, respectively. Even though autophagy could impact several facets of human biology and disease, it generally functions as a clearance for toxic proteins in the brain, which contributes novel insight into the pathophysiological understanding of neurodegenerative disorders. In particular, several studies demonstrate that natural compounds or small molecule autophagy enhancer stimuli are essential in the clearance of amyloid ${\beta}$ and ${\alpha}-synuclein$ deposits. Therefore, this review briefly deliberates on the recent implications of autophagy in neurodegenerative disorder control, and emphasizes the opportunities and potential therapeutic application of applied autophagy.

Degradation of Collagens, Immunoglobulins, and Other Serum Proteins by Protease of Salmonella schottmulleri and its Toxicity to Cultured Cells

  • Na, Byoung-Kuk;Kim, Moon-Bo;Song, Chul-Yong
    • Journal of Microbiology
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    • 제34권1호
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    • pp.95-100
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    • 1996
  • The effect of the extracellular protease of Salmonella schottmulleri on human serum constituents such as immunoglobulins, hemoglobin and lysozyme and tissue constituents such as fibronectin and collagens was investigated. This protease degraded collagens (type I and III), fibronectin and serum proteins such as human hemoglobin and lysozyme. Bovine serum albumin was degraded slightly. Thus, the present study suggested the possibility that this protease is not only played an important role in invasion of S. schottmulleri by degrading the constituent proteins such as collagens and fibronectin but also induced complications observed in septicemia and chronic infections by degrading the serum proteins. This protease is also capable of degrading defence-oriented humoral proteins, immunoglobulins (IgG and IgM). Furthermore, it is toxic to HEp-2 cells. These findings clarified the possible role of Salmonella protease as a virulence factor in the pathogenesis of Salmonella infections.

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Bacillus thuringiensis var kurstaki HD-1의 내독소 단백질 유전에 관여하는 plasmid의 결정 (Determination of Plasmids Encoding Crystal Toxic Protein Gene in Bacillus thuringiensis var kurstaki HD-1)

  • 김철영;김상현
    • 한국잠사곤충학회지
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    • 제35권2호
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    • pp.120-128
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    • 1993
  • B. t k HD-1 균주에 0.002% SDS와 0.5$\mu$g/ml EtBr을 처리한 결과, 9개의 cry- 변이균주를 분리하였으며 또한 B. t k HD-1균주와 B. cereus 569균주를 혼합배양하는 방법으로 mating 실험을 수행하여 B. t k HD-1으로부터 일부 plasmid가 전이된 11개의 cry+ B. cereus와 2개의 cry=B. cereus를 분리하고 plasmid수와 분자량을 조사하였다. B. t k HD-1의 경우 9개의 plasmid가 존재하였고 일부 plasmid가 curing된 B. t k HD-1변이균주의 경우 29Md plasmid나 44Md plasmid가 반드시 존재하였으나, cry- 변이균주에는 29Md 이상의 모든 plasmid가 소실되어 내독소 단백질 합성에 관여하는 유전자가 기억된 plamid를 결정하였다.

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