Use of sialylated or sulfated derivatives and acrylamide copolymers of Gal beta 1,3GalNAc alpha- and GalNAc alpha- to determine the specificities of blood group T- and Tn-specific lectins and the copolymers to measure anti-T and anti-Tn antibody levels in cancer patients.
Sialylated or sulfated derivatives and acrylamide copolymers of blood group T-(Gal beta 1,3GalNAc alpha-) and Tn-(GalNAc alpha) haptens were studied for their interaction with the lectins of peanut (PNA), Agaricus bisporus-(ABA), Helix pomatia-(HPA) and Vicia villosa B4-(VVA), using asialo Cowper's gland mucin (ACGM), which contains both T and Tn epitopes, as the coating substrate in enzyme linked lectin assay. Both T and Tn copolymers (-40 haptens) showed high affinity and strict specificity; although the T-copolymer at 0.05-0.07 microM concentration caused 50% inhibition of interaction of either PNA or ABA with ACGM, there was little inhibition of the HPA and VVA interactions even at over 100 times that concentration. The Tn-copolymer at 0.02-0.05 microM inhibited HPA or VVA interaction with ACGM by 50% but gave virtually no inhibition of PNA and ABA binding. Sialyl, sulfate or methyl group substitution on C-6 of GalNAc of the T-haptene did not prevent interaction with PNA but almost abolished interaction with ABA. In contrast, sialyl or sulfate group on C-6 and sulfate on C-3 of Gal in Gal beta 1,3GalNAc alpha- inhibited almost completely the interaction of PNA with ACGM but had only a slight effect on the interaction of ABA; C-6 substitution with either sialic acid or sulfate on GalNAc alpha- almost abolished the interaction of both HPA and VVA with ACGM.(ABSTRACT TRUNCATED AT 250 WORDS)
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