Anthrax Lethal Factor
Mostrando 1-12 de 66 artigos, teses e dissertações.
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1. Proposta de protocolos de segurança para a prevenção, a contenção e a neutralização de agente agressor bioativo em incidentes bioterroristas e estudo por docking molecular do fator letal do Bacillus anthracis (Antraz)
Há séculos agentes infecciosos são utilizados como armas em conflitos bélicos. Em 1972 a Convenção sobre Armas Biológicas proibiu a criação e armazenamento de armas biológicas. No entanto alguns países continuaram a pesquisa e o desenvolvimento dessas armas. Prova desse fato foi o acidente em 1979 em uma fábrica militar na URSS, onde foram disper
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/10/2010
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2. Apoptosis and melanogenesis in human melanoma cells induced by anthrax lethal factor inactivation of mitogen-activated protein kinase kinase
Lethal factor, the principal virulence factor of Bacillus anthracis, inhibits mitogen-activated protein kinase (MAPK) signaling by proteolytically cleaving MAPK kinases. Edema factor, another component of anthrax toxin, is an adenylate cyclase, which increases intracellular cAMP. Inhibition of MAPK signaling with either anthrax lethal toxin (LeTx) or small m
The National Academy of Sciences.
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3. Study of Immunization against Anthrax with the Purified Recombinant Protective Antigen of Bacillus anthracis
Protective antigen (PA) of anthrax toxin is the major component of human anthrax vaccine. Currently available human vaccines in the United States and Europe consist of alum-precipitated supernatant material from cultures of toxigenic, nonencapsulated strains of Bacillus anthracis. Immunization with these vaccines requires several boosters and occasionally ca
American Society for Microbiology.
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4. A fragment of anthrax lethal factor delivers proteins to the cytosol without requiring protective antigen
Anthrax protective antigen (PA) is a 735-aa polypeptide that facilitates the exit of anthrax lethal factor (LF) from the endosome to the cytosol where the toxin acts. We recently found, however, that a fusion protein of the detoxified N-terminal domain of lethal factor (LFn) with a foreign peptide could induce CD8 T cell immune responses in the absence o
National Academy of Sciences.
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5. Human α-defensins neutralize anthrax lethal toxin and protect against its fatal consequences
Anthrax caused by Bacillus anthracis represents a major bioterroristic threat. B. anthracis produces lethal toxin (LeTx), a combination of lethal factor (LF) and protective antigen that plays a major role in anthrax pathogenesis. We demonstrate that human neutrophil α-defensins are potent inhibitors of LF. The inhibition of LF by human neutrophil protein (H
National Academy of Sciences.
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6. Calcium is required for the expression of anthrax lethal toxin activity in the macrophagelike cell line J774A.1.
Anthrax lethal toxin, which consists of two separate proteins, protective antigen (Mr, 82,700) and lethal factor (Mr, approximately 83,000), is cytotoxic to the macrophagelike cell line J774A.1. Removal of calcium from the culture medium protected cells against the action of lethal toxin. Calcium depletion during the binding phase of intoxication afforded on
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7. On the role of macrophages in anthrax.
Bacillus anthracis, the causative agent of anthrax, produces systemic shock and death in susceptible animals, primarily through the action of its lethal toxin. This toxin, at high concentrations, induces lysis of macrophages in vitro but shows little or no effect on other cells. We found that when mice were specifically depleted of macrophages by silica inje
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8. Purification of Anthrax Edema Factor from Escherichia coli and Identification of Residues Required for Binding to Anthrax Protective Antigen
The structural gene for anthrax edema factor (EF) was expressed in Escherichia coli under the control of a powerful T5 promoter to yield the 89-kDa recombinant protein that reacted with anti-EF antibodies. Recombinant EF was purified to homogeneity by a two-step procedure involving metal chelate affinity chromatography and cation-exchange chromatography. Fro
American Society for Microbiology.
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9. Protein synthesis is required for expression of anthrax lethal toxin cytotoxicity.
Anthrax lethal toxin, which is composed of two proteins, i.e., protective antigen and lethal factor, is cytolytic to mouse peritoneal macrophages and the macrophage-like cell line J774A.1. After exposure of cells to lethal toxin, inhibition of protein synthesis occurred only slightly before the onset of cytolysis. Thus, cell death did not appear to be due to
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10. Role of Toxin Functional Domains in Anthrax Pathogenesis
We investigated the role of the functional domains of anthrax toxins during infection. Three proteins produced by Bacillus anthracis, the protective antigen (PA), the lethal factor (LF), and the edema factor (EF), combine in pairs to produce the lethal (PA+LF) and edema (PA+EF) toxins. A genetic strategy was developed to introduce by allelic exchange specifi
American Society for Microbiology.
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11. Anthrax lethal factor represses glucocorticoid and progesterone receptor activity
We report here that a bacterial toxin, anthrax lethal toxin (LeTx), at very low concentrations represses glucocorticoid receptor (GR) transactivation in a transient transfection system and the activity of an endogenous GR-regulated gene in both a cellular system and an animal model. This repression is noncompetitive and does not affect ligand binding or DNA
The National Academy of Sciences.
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12. Characterization of macrophage sensitivity and resistance to anthrax lethal toxin.
Anthrax lethal toxin, which consists of two proteins, protective antigen and lethal factor, is cytolytic for macrophages. Macrophages from different mouse strains were found to vary in their sensitivities to toxin. C3H mouse macrophages lysed by lethal factor concentrations of 0.001 micrograms/ml were 100,000 times more sensitive than those from resistant A/