Carbohydrate-binding proteins from the sieve-tube sap of Robinia pseudoacacia L.

Evidence is provided for the occurrence of lectins (phytohemagglutinins) in the sieve-tube sap of Robinia pseudoacacia L. The most potent sugars found to inhibit the complex formation of the soluble protein with rabbit erythrocytes were N-acetyl-galactosamine and glycosides containing galactose. Sucrose and inositol had weaker effects. The extract of the membraneous material present in the sieve-tube sap also contains lectins, but the sugar specifity is different.