[Structural characteristics of the blood group N determinant, tested with anti-N lectin from Vicia graminea]

Crude extracts of Vicia graminea seeds agglutinate human N erythrocytes as anti-N immunsera. The anti-N lectin is purified after precipitations with ammonium sulphate of crude extracts, DE52 Whatman chromatography and sephadex G150 gel filtration. Its homogeneity is demonstrated by physical and immunological methods. The structure determinant for the Vicia graminea anti-N activity was investigated: --with the major glycoprotein of N erythrocytes. --with glycoconjugates isolated from urine of normal human N-blood group as urinary glycoconjugates are probably related to the membrane glycoprotein catabolism. Purification and characterization of glycoconjugates are undertaken by gel filtration and non-exchange chromatography. This purification is checked by hemagglutination-inhibition test with V. graminea lectin. Biochemical characterization of active glycoconjugates gives way to the carbohydrate determinant recognized by anti-N antisera and Vicia graminea lectin.