Ultrastructural localization of 'anixiopsin': a lectin of the fungus Anixiopsis stercoraria (Hansen) Hansen.

In order to localize the 'anixiopsin', a lectin of the keratinolytic fungus Anixiopsis stercoraria, the authors used a monospecific antiserum prepared by immunization of rabbits with their own erythrocytes coated in vitro with 'anixiopsin'. In light and scanning electron microscopies, lectinic sites were visualized by means of latex microspheres sensitized with anti-rabbit IgG antibodies. In transmission electron microscopy using the IgG fraction of the rabbit anti-anixiopsin immune sera and protein A-gold, 'anixiopsin' seemed mainly present on the outermost cell wall layer of the ascospores, in a pseudomembraneous structure dense to electrons. Implications of these results on physical and biological properties of the lectin are discussed.