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dc.creatorUrbina, Patriciaes_ES
dc.creatorFlores Díaz, Mariettaes_ES
dc.creatorAlape Girón, Albertoes_ES
dc.creatorAlonso, Aliciaes_ES
dc.creatorGoni, Félix M.es_ES
dc.date.accessioned2012-04-24T10:38:59Zes_ES
dc.date.available2012-04-24T10:38:59Zes_ES
dc.date.issued2009-02es_ES
dc.identifier.citationhttp://www.journals.elsevier.com/chemistry-and-physics-of-lipids/#descriptiones_ES
dc.identifier.issn0009-3084es_ES
dc.identifier.urihttp://hdl.handle.net/10669/606es_ES
dc.description.abstractAlfa-Toxin is a major pathogenic determinant of Clostridium perfringens, the causative agent of gas gangrene. Alfa-Toxin has been known for long to be a phospholipase C, but up to now its hydrolytic properties have been studied only through indirect methods, e.g. release of cell contents, or under non-physiological conditions, e.g., in micelles, or with soluble substrates. In this report we characterize the phospholipase C and sphingomyelinase activities of Alfa-toxin using a direct assay method (water-soluble phosphorous assay) with phospholipids in bilayer form (large unilamellar vesicles) in the absence of detergents. The simplest bilayer compositions allowing measurable activities under these conditions were DOPC:Chol (2:1 mol ratio) and SM:PE:Chol (2:1:1 mol ratio) for the PLC and SMase activities respectively. PLC activity was five times higher than SMase activity. Both activities gave rise to vesicle aggregation, after a lag time during which ca. 10% of the substrate was hydrolyzed. Vesicle aggregation, measured as an increase in light scattering, was a convenient semi-quantitative method for estimating the enzyme activities. The optimum pH for the combined PLC and SMase activities was in the 5–7 range, in agreement with the proposed role of -toxin in aiding the bacterium to escape the fagosome and survive within the cytosol.es_ES
dc.description.sponsorshipCIEMIC e Instituto Clodomiro Picado, Universidad de Costa Rica. Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU), y Departamento de Bioquímica, Universidad del País Vasco, España.es_ES
dc.language.isoen_USes_ES
dc.publisherChemistry and Physics of Lipidses_ES
dc.subjectPhospholipase Ces_ES
dc.subjectSphingomyelinasees_ES
dc.subjectLiposome aggregationes_ES
dc.subjectClostridiumes_ES
dc.subjectAlfa-toxines_ES
dc.titlePhospholipase C and sphingomyelinase activities of the Clostridium perfringens Alfa-toxines_ES
dc.typeartículo científicoes_ES
dc.identifier.doi10.1016/j.chemphyslip.2009.02.007es_ES
dc.description.procedenceUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología


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