Alterations of the specificity of lectin by chemical modification. IV. Further purification and alteration of the specificity of a snail lectin by chemical modification.

The anti-A agglutinin of the snail Otala lactea, the most potent non-immune source of anti-A thus far discovered, was partially purified and studied serologically. Studies were made of the effect of chemical alteration on the specificity. Coupling diazotized p-aminophenyl-α-N-acetyl-[(14)C]galactoside to the purified lectin greatly enhanced the agglutinating activity of the lectin for group B erythrocytes, without significantly affecting its activity for A(1), A(2) or 0 (no anti-0 activity) cells. Treatment of the lectin with phenylazo-benzoyl [(14)C] (PAB)chloride did not significantly alter its activity or specificity. The anti-B activity conferred by the first of these treatments could be inhibited by sufficient amounts of galactose.