Partial characterisation of cholera toxin binding of membranes of saccharomyces boulardii

Abstract

In the study reported here we demonstrated the presence of specific binding sites for cholera toxin on S. boulardii membranes using 125I-cholera toxin.The 125I-toxin bound very effectively to the membrane preparation of S. boulardii with a minimum detectable concentration of 0.5 nM and saturation being achieved at 4 nM. The binding was displaced by very low concentration of native cholera toxin. The displacement of 125I-cholera toxin from the membranes was a rapid phenomenon with 50

of the binding displaced in about 15 min and 50 percent of the dissociation obtained at a concentration of approximately 0.5 x 10-8 M. The present results indicate a possible new prophylactic method against infections involving oral intake of S. boulardii cells to flush cholera toxin or other cholera-like toxins (Escherichia coli) from the intestinal ecosystem.