title: Purification and saccharide-binding characteristics of a rice lectin.
abstract: A lectin was purified from rice flour by aqueous extraction followed by precipitation by ammonium sulfate and affinity chromatography on p-aminobenzyl 2-acetamido-2-deoxy-1-thio-beta-D-glucoside-succinyl-aminohexylaminyl -Sepharose 4B. The molecular weight of the lectin is approximately 36,000, as determined by sedimentation-equilibrium analysis. It is a tetramer consisting of two different subunits (Mr = 12,000 +/- 1,000 and 9,000 +/- 1,000). Amino acid analysis indicated that the lectin contains very high proportions of half-cystine, glycine, and glutamic acid. All of the half-cystines are present as -S-S- bridges. The lectin agglutinates human A, B, AB, and O erythrocytes, rabbit erythrocytes, human leukocytes, and is mitogenic to human lymphocytes. The hemagglutinating activity of rice lectin is inhibited by 2-acetamido-2-deoxy-D-glucose, methyl 2-acetamido-2-deoxy-beta-D-glucoside, chitobiose, and chitotriose. N-Acetylneuraminic acid was a noninhibitor, but N-acetylneuramin-(2----3)-lactose showed weak inhibition. The agglutinating activity was also inhibited by various sialoglycoproteins. The immobilized rice-lectin bound glycophorin, alpha 1-acid glycoprotein, and fetuin. Asialoglycophorin, asialofetuin, ovomucoid, and human chorionic gonadotropin were bound only partially to the column.
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates; D002846:Chromatography, Affinity / Q000379:methods; D004912:Erythrocytes / Q000276:immunology; D006384:Hemagglutination; D006385:Hemagglutination Inhibition Tests; D006386:Hemagglutination Tests; D006801:Humans; D037102:Lectins / Q000302:isolation & purification*; D008213:Lymphocyte Activation; D008970:Molecular Weight; D012275:Oryza; D037121:Plant Lectins; D011817:Rabbits; D013329:Structure-Activity Relationship
chemical_list: D000017:ABO Blood-Group System; D000596:Amino Acids; D002241:Carbohydrates; D037102:Lectins; D037121:Plant Lectins; C040599:rice lectin