title: The interaction of concanavalin A with blood-group-substance glycoproteins from human secretions.
abstract: 1. Gastric juice, saliva and ovarian-cyst fluid were fractionated into glycoprotein components by centrifuging to equilibrium in a caesium chloride density gradient. 2. The glycoprotein fractions from the gastric juice of two group O non-secretors, two group O secretors and three group A secretors all formed insoluble complexes with concanavalin A. 3. Fractions showing maximum interaction with concanavalin A had maximum blood-group activity measured by the haemagglutination-inhibition technique. The sulphate content of the gastric glycoproteins was unrelated to the capacity to interact with concanavalin A. 4. No interaction was found between concanavalin A and the glycoprotein fractions from any of the saliva or ovarian-cyst-fluid samples tested, implying that there is a structural difference in blood-group-substance glycoproteins in gastric juice when compared with those in saliva and ovarian-cyst fluid. 5. The protein components of each of the secretions tested, gastric juice, saliva and ovarian-cyst fluid, interacted with concanavalin A.
mesh_terms: D000017:ABO Blood-Group System / Q000378:metabolism; D001826:Body Fluids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D002499:Centrifugation, Density Gradient; D011232:Chemical Precipitation; D003208:Concanavalin A; D003720:Densitometry; D005260:Female; D005750:Gastric Juice / Q000032:analysis; D006023:Glycoproteins; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D037102:Lectins; D007983:Lewis Blood Group Antigens; D010048:Ovarian Cysts / Q000276:immunology; D012463:Saliva / Q000032:analysis; D013431:Sulfates / Q000032:analysis
chemical_list: D000017:ABO Blood-Group System; D002241:Carbohydrates; D006023:Glycoproteins; D037102:Lectins; D007983:Lewis Blood Group Antigens; D013431:Sulfates; D003208:Concanavalin A