RESUMEN
The N-acetyl-galactosamine specific lectin from Macrotyloma axillare seeds (LMA) was purified by precipitation and ion exchange chromatography. The LMA 0.2 mol L(-1) fraction showed hemagglutinating activity on erythrocytes A1. The results for molecular mass determinations were about 28 kDa. The LMA pH-dependent assays showed best hemagglutinating activity at pH 6.0-8.0; being decreased at acidic/alkaline conditions and by EDTA treatment. LMA is a tetramer at pH 8.2 and a dimer at pH 4.0. Human erythrocytes from ABO system confirmed the A1 specificity for LMA. This new methodology is useful and easy, with low costs, for lectin purification in large amounts.
Asunto(s)
Bioquímica/economía , Bioquímica/métodos , Fabaceae/química , Lectinas de Plantas/aislamiento & purificación , Semillas/química , Calcio/farmacología , Precipitación Química , Cromatografía en Gel , Cromatografía por Intercambio Iónico , Mezclas Complejas/química , Ácido Edético/farmacología , Electroforesis en Gel de Poliacrilamida , Etanol , Hemaglutinación/efectos de los fármacos , Humanos , Concentración de Iones de Hidrógeno/efectos de los fármacos , Manganeso/farmacología , Peso Molecular , Lectinas de Plantas/química , Espectrometría de Masa por Ionización de Electrospray , TemperaturaRESUMEN
Schistosoma mansoni is 1 of the causative agents of schistosomiasis, an endemic disease in 76 countries of the world. The study of its genome, estimated to be 270 Mb, is very important to understanding schistosome biology, the mechanisms of drug resistance, and immune evasion. Repetitive elements constitute more than 40% of the S. mansoni genome and may play a role in the parasite evolution. The retrotransposons Boudicca, a long terminal repeat (LTR), and Perere 03, a non-LTR, are present in a high number in the S. mansoni genome and were localized with the use of fluorescence in situ hybridization (FISH) and primed in situ labeling (PRINS). Bacterial artificial chromosomes (BAC) clones containing the retrotransposons Boudicca and Perere 03 were selected by bioinformatic analysis and used as probes in FISH. Using metaphase chromosomes from sporocysts and the FISH and PRINS techniques, we were able to map these retrotransposons. Perere 03 was localized in the euchromatic regions of the short arm of chromosome 2 and Boudicca in the euchromatic regions of the short arm of chromosomes 2 and Z.
Asunto(s)
Genoma de los Helmintos/genética , Retroelementos/fisiología , Schistosoma mansoni/genética , Animales , Mapeo Cromosómico/métodos , Cromosomas Artificiales Bacterianos/genética , Hibridación Fluorescente in Situ , Cariotipificación , Microscopía Confocal , Etiquetado in Situ Primed , Alineación de Secuencia , Secuencias Repetidas TerminalesRESUMEN
The present work describes the identification of toxins expressed by the venom gland of the spider Lasiodora sp. The toxins LTx1, LTx2 and LTx3 were identified by the screening of a cDNA library. These toxins showed significant similarity at the amino acid level with spider toxins from Lasiodora parahybana, Eurypelma californicum, Brachypelma smithii, Selenocosmia huwena.
Asunto(s)
Venenos de Araña/química , Arañas/química , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Expresión Génica , Datos de Secuencia Molecular , Alineación de Secuencia , Especificidad de la EspecieRESUMEN
We have produced a fragment of hepatitis B surface antigen (HBsAg) corresponding to amino acids 1-60 as a fusion protein with the alpha mating factor of yeast. The product is secreted from yeast as a soluble monomer that expresses HBsAg antigenicity. Unlike other heterologous fusion proteins, it is not processed by the Lys-Arg endoprotease, possibly due to a proline in the linker between the two coding sequences. The resulting soluble fragment will enable us to map the immunodominant sites of HBsAg recognized by T cells and to identify additional factors contributing to vaccine potency.
Asunto(s)
Antígenos de Superficie de la Hepatitis B/genética , Péptidos/genética , Saccharomyces cerevisiae/genética , Secuencia de Aminoácidos , Secuencia de Bases , ADN Viral/genética , ADN Viral/aislamiento & purificación , Escherichia coli/genética , Vectores Genéticos , Antígenos de Superficie de la Hepatitis B/biosíntesis , Antígenos de Superficie de la Hepatitis B/aislamiento & purificación , Virus de la Hepatitis B/genética , Factor de Apareamiento , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos/síntesis química , Biosíntesis de Péptidos , Fragmentos de Péptidos/biosíntesis , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/aislamiento & purificación , Péptidos/aislamiento & purificación , Feromonas/genética , Plásmidos , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/aislamiento & purificación , Mapeo Restrictivo , Transformación GenéticaRESUMEN
Attempts have been made to characterize two strains of Leishmania that became infective to golden hamsters only after they had been maintained for several years in a chemically defined culture medium. Observations were made on the growth rates of promastigotes in vitro, course of infection in hamsters, morphology of amastigotes, and electrophoretic mobility patterns of eight isoenzymes. Information was obtained about the buoyant densities of n-DNA and k-DNA, and one strain was tested against monoclonal antibodies. The identity of both strains remains obscure.
Asunto(s)
Cricetinae/parasitología , Leishmania/patogenicidad , Animales , Medios de Cultivo , Electroforesis en Gel de Almidón , Humanos , Isoenzimas/análisis , Leishmania/enzimología , Leishmania/crecimiento & desarrollo , Leishmaniasis/parasitología , Masculino , Mesocricetus , Ratones , Ratones EndogámicosRESUMEN
Duas cepas de Leishmania originalmente isoladas in vitro de casos humanos de leishmaniose cutânea e que ab initio näo infectaram animais de laboratório, tornaram-se infectantes para hamnsters após serem mantidos por vários anos em meio de cultura quimicamente definido. Foram realizadas observaçöes sobre o crescimento de promastigotas in vitro, curso da infecçäo em hamsters, morfologia das amastigotas, mobilidade eletroforética de oito enzimas solúveis. Foram obtidas informaçöes sobre a densidade de flutuaçäo do n-DNA e do k-DNA e uma das cepas foi testada contra anticorpos monoclonais. Ambas as cepas permanecem sem identificaçäo precisa