Dynamics of Carbohydrate Affinities at the Cell Surface: INTRODUCTION(2)
The sperm cells contain lectin-like molecules on their cellular surface with affinities for certain carbohydrate moieties on the apical surface of oviduct epithelial cells. Indirectly, these interactions can be studied by the use of competitive carbohydrate-binding inhibition assays. For instance, fetuin and sialic acid specifically block binding of the hamster sperm to the oviduct epithelium, whereas, in equine fetuin, asialofetuin, and galactose have been reported to inhibit binding of the sperm to the ovi-ductal epithelium. canadian neighbor pharmacy
In bovine sperm, binding to the ovi-ductal epithelium can be inhibited by fucose and is even more pronounced by fucoidan (a multimeric fucose moiety). Pretreatment of the bovine oviduct epithelium with fu-cosidase also reduces sperm binding. From different fucose-containing oligosaccharides, only trisaccharide LewisA (a-l-Fuc-p-D-Gal-d-GlcNAc) significantly reduced binding. This indicates that not only the presence of fucose in a carbohydrate moiety per se but also its position within the carbohydrate moiety determines functional binding.