The capacity of pig gastric mucin-derived glycopeptides to interfere with the binding of cholera toxin (CT) to membrane receptors was studied. Two types of glycopeptide preparations with or without human blood group A antigenic activity were assayed for comparison in a system in which the target for the toxin was rat erythrocyte ghosts. Blood group A-active glycopeptides (A+ glycopeptides) were...

<p>In this work, the ONIOM method, recognized for its effectiveness on large molecules, was used to determine geometric, energetic, and spectroscopic parameters of hydrogen bond interactions mycolactone C. Mycolactone C; one most virulent forms toxin, found in Africa Australia. It has eight (08) oxygen heteroatoms which are all hybridized sp<sup>2</sup> sp<sup>3</sup&...

Evolution of resistance by insects threatens the continued success of pest control using insecticidal crystal (Cry) proteins from the bacterium Bacillus thuringiensis (Bt) in sprays and transgenic plants. In this study, laboratory selection with Cry1Ac yielded five strains of cotton bollworm, Helicoverpa armigera, with resistance ratios at the median lethal concentration (LC50) of activated Cry...

Clostridium perfringens iota-toxin consists of two separate proteins identified as a cell binding protein, iota b (Ib), which forms high-molecular-weight complexes on cells generating Na(+)/K(+)-permeable pores through which iota a (Ia), an ADP-ribosyltransferase, presumably enters the cytosol. Identity of the cell receptor and membrane domains involved in Ib binding, oligomer formation, and in...

In this article, we present the use of micron-sized lipid domains, patterned onto planar substrates and within microfluidic channels, to assay the binding of bacterial toxins via total internal reflection fluorescence microscopy. The lipid domains were patterned using a polymer lift-off technique and consisted of ganglioside-populated distearoylphosphatidylcholine:cholesterol supported lipid bi...

The effects of mucin on cholera toxin induced intestinal secretion was studied in the rat small intestine. Gastric mucin inhibited secretion when premixed with cholera toxin on an equal dry-weight basis. Neither salivary nor intestinal mucin inhibited the toxin's action in the intestine. Inhibition by gastric mucin was not reversed by a mucolytic agent or by hexoses or agents that bind hexoses....

Insecticidal activity and receptor binding properties of Bacillus thuringiensis toxins to yellow and striped rice stem borers (Sciropophaga incertulas and Chilo suppresalis, respectively) were investigated. Yellow stem borer (YSB) was susceptible to Cry1Aa, Cry1Ac, Cry2A, and Cry1C toxins with similar toxicities. To striped stem borer (SSB), Cry1Ac, Cry2A, and Cry1C were more toxic than Cry1Aa ...

The distribution of alpha-bungarotoxin binding sites on chick ciliary ganglion neurons was examined at the ultrastructural level by incubating ganglia with horseradish peroxidase-conjugated toxin and examining the peroxidase-stained and thin-sectioned ganglia with the electron microscope. Both in embryonic and in adult ganglia heavy labeling was restricted to the surface membrane of short proce...

Antibody against T-2 toxin was obtained after immunization of rabbits with bovine serum albumin-T-2 hemisuccinate conjugate. The antibody had greatest binding efficiency for T-2 toxin, less efficiency for HT-2, and least for T-2 triol. Cross-reaction of antibody with neosolaniol, T-2 tetraol, and 8-acetyl-neosolaniol was very weak. Diacetoxyscirpenol, trichodermin, vomitoxin, and verrucarin A e...

An atypical toxin variant of Clostridium botulinum (strain 657) was isolated from the feces of a 6-week-old female infant whose symptoms and clinical history were consistent with infant botulism. Toxin detected in the feces and the toxin produced by isolates from the feces and from two rectal swabs could be neutralized by type B botulinal antitoxin only at very high ratios of of antitoxin to to...