A comparative study of peanut agglutinin and amaranthin binding to human urinary bladder tumor glycoproteins

The reactivity of two T-antigen specific lectins, Amaranthin (ACA) and Peanut Agglutinin (PNA), was compared by immunohistochemical staining of serial sections of human bladder tumors and by Western Blot analysis of glycoproteins extracted from human bladder tumors prior to and after sialic acid removal. In low grade tumors ACA reacted prior to neuraminidase treatment. PNA on the other hand only showed positive reaction in these tumors after neuraminidase treatment. The two lectins showed identical staining patterns after neuraminidase treatment in tumors. In Western blottings both lectins detected a 28 kD glycoprotein. PNA also reacted with several other bands after neuraminidase treatment. The reactivity of ACA was not enhanced after neuraminidase treatment. In monosaccharide inhibition tests ACA- and PNA-binding to different T-antigens was most efficiently inhibited by GalNAc and Gal respectively. PNA binding was also inhibited by Glc, GlcNAc and GalNAc at higher concentrations, while the binding of ACA was only scarcely affected by Glc, GlcNAc and Gal.