RESUMO
The antifungal activity of base-soluble proteins (BSP) and methanol-soluble polysaccharides (PS) from A. flavus resistant (Yellow Creole) and susceptible (Huffman) genotypes of corn were investigated by in vitro studies. Bioassays of fungal growth inhibition in agar media showed antifungal activity by proteins and polysaccharides only from the Huffman genotype. Microgramme quantities of protein and polysaccharides were required to retard fungal growth. The polysaccharides have molecular weights greater than 3.5 kilodaltons. Cathodic PAGE of native protein from the two genotypes showed six protein bands with differences in staining intensity of individual components. SDS-PAGE showed four distinct bands in Yellow Creole that were absent in Huffman. Both of the protein samples contained traces of carbohydrate. Analysis of hydrolyzed polysaccharide from the two genotypes showed different proportions of mannose and glucose.
Assuntos
Aspergillus flavus/crescimento & desenvolvimento , Proteínas de Plantas/farmacologia , Polissacarídeos/farmacologia , Zea mays/análise , Aspergillus flavus/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Glucose/análise , Manose/análise , Metanol , Peso Molecular , Proteínas de Plantas/análise , Proteínas de Plantas/química , Polissacarídeos/análise , Polissacarídeos/química , Solubilidade , Zea mays/microbiologiaRESUMO
A crude polysaccharide that hemolyzed human red blood cells of the ABO types was isolated from the condensed tannin fraction of Sorghum bicolor. It contained primarily 2-hydroxybenzoic acid and glucose and had a molecular weight of greater than 6000. Limit hemolytic activity for each of four blood group cells corresponded to a range of 110-27 micrograms of carbohydrate per assay.
Assuntos
Grão Comestível/análise , Hemólise/efeitos dos fármacos , Polissacarídeos/farmacologia , Liofilização , Humanos , Técnicas In VitroRESUMO
A competitive enzyme-linked immunosorbent assay was developed for the xanthone dimer secalonic acid D. The immunogen and enzyme marker were prepared by direct reaction of secalonic acid D with bovine serum albumin and horseradish peroxidase, respectively. The resultant conjugates were characterized by UV/VIS spectra and thin layer chromatography. The hapten:protein ratios in the conjugates were estimated by difference UV/VIS spectra and by fluorescent techniques. Immunization procedures were conducted utilizing New Zealand rabbits over a period of 12 weeks. The competitive enzyme-linked immunosorbent assay on microtiter plates showed that secalonic acid D was detectable within a range of 250-25 000 ng/assay.
Assuntos
Xantenos/análise , Xantonas , Animais , Cromatografia em Camada Fina , Ensaio de Imunoadsorção Enzimática , Peroxidase do Rábano Silvestre , Coelhos , Soroalbumina Bovina , Xantenos/imunologiaRESUMO
The aflatoxins are a family of complex coumarins produced by species of Aspergillus that are toxic and carcinogenic in animals. Four of the naturally occurring aflatoxins (B1, B2, G and G2) were incubated in vitro with whole human serum and subsequently tested for effects on antigenicities and electrophoretic mobilities of the proteins. Immunoelectrophoresis showed deviations of some of the precipitin arcs from normal patterns. Double diffusion experiments with affinity-isolated antibodies that are specific for the heavy chains of immunoglobulins IgA, IgG and IgM showed that the antigen-antibody binding sites of the heavy chains of IgA and IgM were blocked after incubation, but not those of IgG. These results are of interest regarding the specificity of immunochemical reactions in vitro that might be linked to specific immunological responses in diseases mediated by these toxins.
