Isolation of Lectin Binding Glycoproteins from Normal and Malignant Gastric Mucosa

Abstract Lectins (PNA, WGA, Con A, and UEA I) covalently coupled to agarose were used to isolate glycoproteins from the Triton X-100 extracts of normal and malignant gastric mucosal scrapings. Although the isolated glycoproteins belonged almost exclusively to the high molecular weight (HMW) mucus, their gel filtration and electrophoretic properties as well as their hexose composition showed some characteristic differences. The high aminohexose values of the lectin-affinity isolated normal mucus and their elevated amount in adenocarcinoma extracts suggest that the lectin receptors are localized in the core and backbone region of the oligosaccharide chains. This assumption is supported by immunohistological findings, since antibodies raised against the lectin-affinity isolated mucus, showed a wider distribution both in normal and carcinomatous tissues than the lectins alone.